Article

Validity of Skin, Oral and Tympanic Temperatures During Exercise in the Heat: Effects of Wind and Sweat

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Abstract

This experiment investigates the validity of six thermometers with different measuring sensors, operation and site of application, to estimate core temperature (Tc) in comparison to an ingestible thermometric sensor based on quartz crystal technology. Measurements were obtained before, during and after exercise in the heat, controlling the presence of air-cooling and skin sweating. Twelve well-trained men swallowed the ingestible thermometer 6 h before the trial. After pre-exercise resting measurements at 20 °C, subjects entered a heat chamber held at 40 °C. Exercise in the heat consisted of 60 min of pedalling on cycle ergometer at 90% of the individually determined first ventilatory threshold. Results reveal that wind and skin sweat invalidate the use of skin infrared thermometry to estimate Tc during exercise in the heat. However, better Tc estimations were obtained in wind-restricted situations. We detected important differences between same-technology devices but different models and brands. In conclusion, there are important limitations to assess Tc accurately using non-invasive thermometers during and after exercise in the heat. Because some devices showed better validity than others did, we recommended using tympanic Braun®, and non-contact skin infrared Medisana® or Visiofocus® in wind-restricted and no sweat conditions to estimate Tc during exercise in the heat.

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... Yeoh et al. (2017) revisited this problem, suggesting that greater agreement between T c and tympanic temperatures can be obtained when the tympanic thermometer is correctly pointed at the tympanic membrane. Improved agreement was recently demonstrated, whereby a tympanic thermometer registered a mean difference of 0.1 ± 1.9°C (± 95% limits of agreement [LoA]) during exercise in the heat compared to an ingestible T c pill (Morán-Navarro et al., 2018). ...
... Technological advances in the design and specificity of tympanic membrane thermometers and infrared cameras have the potential to limit the bias between laboratory-based devices and in field, practical temperature measurement (Morán-Navarro et al., 2018). Hence, the purpose of the current study was to compare laboratory-based invasive measures of T c (BodyCap, Caen, France; ingestible telemetry pill) and T sk (hard-wired skin thermistors) with minimally invasive, practical devices designed to measure T c (Braun ThermoScan® 7; tympanic membrane thermometer) and skin temperature (ICI ToughCam EL Scientific, Infrared Cameras Incorporated, Texas, USA; handheld infrared imager) pre, during, and post exercise in the heat. ...
... Weighted mean T sk assessment resulted in an unacceptable mean bias of 0.6°C between devices, and the correlation between mean T sk(T) and mean T sk(IR) was moderate (r = 0.61), with T sk(IR) reading higher temperatures across all timepoints. These results support those of Morán-Navarro et al. (2018), who recently showed that a tympanic thermometer (Braun ThermoScan® 7; the same model as used in the current study) registered similar temperatures to a telemetry pill system (CorTemp® system; HQ Inc., Florida, USA), with variations of just~0.1°C at rest and during exercise in the heat. ...
This study compared criterion to minimally invasive, practical measures of core (Tc) and skin (Tsk) temperature during 30 min of moderate-intensity cycle exercise in a heat chamber (35°C, 60% rH). Tc was monitored using a core temperature pill (Tc(Pill)) and tympanic thermometer (Tc(Tymp)) during rest, exercise, and recovery in 15 participants. Tsk was monitored using hard-wired skin thermistors attached to a data logger (Tsk(T)) and a thermal imaging camera (Tsk(IR)) in 11 participants. Tc measurement resulted in no significant difference (p > 0.05), a mean bias of 0.1°C, coefficient of variation (CV%) of 1.0%, and correlation of r = 0.74 between devices. Tsk measurement resulted in a significant difference (p = 0.01), a mean bias of 0.6°C, CV% of 2.3%, and correlation of r = 0.61 between devices. Tc(Tymp) demonstrated acceptable agreement with Tc(Pill); however, caution is advised when using Tsk(IR) to give accurate measures of Tsk during exercise.
... temperature pills [33], esophageal temperature [6], tympanic and non-contact method in the present study) or to the differences in environment temperatures. Notwithstanding, the accuracy and validity of non-invasive thermometers was criticized [41], recent studies recommended the use of tympanic and non-contact skin methods during and after exercise in the heat [41,42]. The present study reveals increases in tympanic and body temperature at the end of all WU durations with more relevant increases observed after the WU15 and WU20 durations compared to WU10. ...
... temperature pills [33], esophageal temperature [6], tympanic and non-contact method in the present study) or to the differences in environment temperatures. Notwithstanding, the accuracy and validity of non-invasive thermometers was criticized [41], recent studies recommended the use of tympanic and non-contact skin methods during and after exercise in the heat [41,42]. The present study reveals increases in tympanic and body temperature at the end of all WU durations with more relevant increases observed after the WU15 and WU20 durations compared to WU10. ...
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Background This study addressed the lack of data on the effect of warm-up (WU) duration in hot-dry climate (~ 30 °C; ~ 18% RH), on thermoregulation, muscular power-output, and fatigue after specific soccer repeated-sprint test (RSA). Methods Eleven amateur soccer players participated in a cross-over randomized study and they underwent the Bangsbo repeated-sprint test, after three WU durations (i.e. WU10, WU15 and WU20 min) at 70% of MAV, and on different days. Peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analyzed. Likewise, heart rate (HR), tympanic temperature (Ttym), mean body temperature (MBT) and rating of perceived exertion (RPE) were recorded during each session. Results The repeated measure ANOVA showed that MP improved after WU15 in comparison to WU10 and WU20 (p = 0.04 and p = 0.001; respectively). Nonetheless, no significant effect on PP was recorded after all WU durations. FI during RSA increased after WU20 in comparison to WU15 and WU10 (p < 0.001 and p = 0.003; respectively). Higher RPE values (p < 0.001) were recorded after WU15 and WU20 in comparison to WU10 duration. The two-way ANOVA showed higher ΔTtym and ΔMBT values after WU15 and WU20 compared to WU10 (p = 0.039 and p < 0.001for Ttym; p = 0.005 and p < 0.001 for MBT, respectively). Conclusions The WU15 at 70% of MAV better assists mean power-output during soccer RSA in hot-dry (~ 30 °C; 18% RH) climate, but not peak power. Reducing WU duration up to 10 min seems to be insufficient to induce beneficial physiological changes necessary for optimizing repeated-sprint performance, while its extension up to 20 min remains detrimental for muscular power and induces higher fatigue.
... Various studies investigated the reliability of this thermometer for measuring the tympanic temperature. Navarro et al. concluded Braun thermoscan IRT 6530 reliably estimates the body temperature during exercise in the heat [18]. To measure the heart rate, pulse monitor with chest strap of Beurer PM70 model with an accuracy of one beat per minute was also applied. ...
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Background Need to a simple, available, accurate, comprehensive, and valid indicator is felt to assess thermal effects. Therefore, the present study was aimed to develop and validate the environmental heat strain risk assessment (EHSRA) index using structural equation modeling (SEM) based on empirical relations. Methods This cross-sectional study was performed on 201 male workers in environments with various climatic conditions. The heart rate and tympanic temperature of the individuals were monitored at times of 30, 60, and 90 min after beginning the work. At these times, values of dry temperature, wet temperature, globe temperature, and air velocity were also measured and metabolism rate and clothing thermal insulation value were estimated. At the end, a theoretical model was depicted in AMOS software and obtained coefficients were applied to develop a novel index. The scores of this indicator were categorized into four risk levels via ROC curves and validate using linear regression analysis. Results Indirect effect coefficients of the globe temperature, dry temperature, wet temperature, air velocity, metabolism, and clothing thermal insulation variables on the tympanic temperature were computed by 0.77, 0.75, 0.69, 0.24, 0.49, and 0.39, respectively. These coefficients were applied to develop the index. Optimal cut-off points of boundaries between risk levels included 12.02, 15.88, and 17.56. The results showed that the EHSRA index justified 75% of the variations of the tympanic temperature ( R ² = 0.75). Conclusions The novel index possesses appropriate validity. It was suggested that this indicator is applied and validated in various environments in the next studies.
... Given that no previous studies investigated the validity of IR-T ty when core temperature was higher than 39.5°C during exercise in the heat (Casa et al. 2007;Coso et al. 2008;Ganio et al. 2009;Hansen et al. 1996;Moŕan-Navarro et al. 2019;Otani et al. 2005), further study is required to verify that IR-T ty may be used for core temperature beyond 39.5°C. Meanwhile, although no other studies have reported on the validity of the T ty thermometer employed in this study during exercise in the heat, Morán-Navarro et al. (2019) showed that brands and manufacturers of various T ty thermometers can influence readings. These limitations should be considered in future studies on the utility of IR-T ty in individuals exercising in hot environments. ...
Article
We investigated the validity of infrared tympanic temperature (IR-Tty) during exercise in the heat with variations in solar radiation. Eight healthy males completed stationary cycling trials at 70% peak oxygen uptake until exhaustion in an environmental chamber maintained at 30°C with 50% relative humidity. Three solar radiation conditions, 0, 250 and 500 W/m², were tested using a ceiling-mounted solar simulator (metal-halide lamps) over a 3 × 2 m irradiated area. IR-Tty and rectal temperature (Tre) were similar before and during exercise in each trial (P > 0.05). Spearman’s rank correlation coefficient (rs) demonstrated very strong (250 W/m², rs = 0.87) and strong (0 W/m², rs = 0.73; 500 W/m², rs = 0.78) correlations between IR-Tty and Tre in all trials (P < 0.001). A Bland-Altman plot showed that mean differences (SD; 95% limits of agreement; root mean square error) between IR-Tty and Tre were − 0.11°C (0.46; − 1.00 to 0.78°C; 0.43 ± 0.16°C) in 0 W/m², − 0.13°C (0.32; − 0.77 to 0.50°C; 0.32 ± 0.10°C) in 250 W/m² and − 0.03°C (0.60; − 1.21 to 1.14°C; 0.46 ± 0.27°C) in 500 W/m². A positive correlation was found in 500 W/m² (rs = 0.51; P < 0.001) but not in 250 W/m² (rs = 0.04; P = 0.762) and 0 W/m² (rs = 0.04; P = 0.732), indicating a greater elevation in IR-Tty than Tre in 500 W/m². Percentage of target attainment within ± 0.3°C between IR-Tty and Tre was higher in 250 W/m² (100 ± 0%) than 0 (93 ± 7%) and 500 (90 ± 10%; P < 0.05) W/m². IR-Tty is acceptable for core temperature monitoring during exercise in the heat when solar radiation is ≤ 500 W/m², and its accuracy increases when solar radiation is 250 W/m² under our study conditions.
... [1][2][3][4] The measurement is challenging even more when sweat or topical products cover the skin surface. [5][6][7] The ingredients of plant-derived revulsive products may induce changes in skin blood flow, affecting skin temperature. [8][9][10][11] To the best of authors' knowledge, to date, no study has compared conductive and contact-free skin temperature measurement methods to perform a continuous observation of the physiological changes induced by revulsive products. ...
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Background Skin temperature assessments comprise conductive and contact‐free techniques. Comparison between conductive data loggers and contact‐free thermometry after the application of revulsive products is scarce. This study aimed to compare iButton data loggers with an infrared thermometer after the application of two revulsive products. Secondly, the relation between skin temperature kinetics with skin's perfusion of microcirculation was investigated. Materials and methods Healthy females (n = 25) were randomly allocated to two groups, representing the products A and B. Skin temperature was measured with “iButtons” and an infrared pistol at baseline and up to 1 hour after application. Skin's perfusion of microcirculation was monitored with a laser speckle contrast imager. Results Baseline “iButton” temperature values were significantly lower compared with infrared pistol values in both groups. After application of the products, skin temperature decreased as recorded with both devices followed by an increase to baseline values when measured with the pistol. The results obtained by the “iButtons” reached values above baseline in both products towards the end of the follow‐up period. A moderate correlation was found between infrared pistol and “iButton” system in product A, with a weak negative correlation between skin's perfusion of microcirculation and temperature devices. For product B, the correlation between the devices was moderate and between skin's perfusion and temperature devices weak and positive. Conclusion Both devices produced similar kinetics, except at baseline, where they may differ as metallic loggers have been insufficiently adapted to skin temperature. Skin's perfusion of microcirculation could not explain skin temperature changes.
... This device, with pre-warmed tips and an exact positioning system, has been registered as a patent. Navarro et al. [26] resulted that Braun thermoscan IRT 6530 accurately estimated the body temperature of subjects during exercise under warm conditions. The heart rate was measured using a pulse monitor of Beurer PM70 with an accuracy of one beat per minute. ...
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Background: There is not a comprehensive heat stress index to screen the people susceptible to heat disorders and illnesses in hot workplaces. The present study was aimed to develop a personal heat strain risk assessment (PHSRA) index in workplaces and validate it. Methods: This cross-sectional study was carried out on 201 Iranian male employees under various thermal conditions. At first, the demographical data of participants were gathered. After that, the heart rate and tympanic temperature of the subjects were carefully measured at times of 30, 60, and 90 min of starting the work. Environmental factors were measured simultaneously. The metabolism rate and insulation value of clothes were also estimated. At the end, a novel index of the heat strain was developed using structural equation modeling in AMOS and validated using linear regression analysis in SPSS. Results: Indirect effect coefficients of personal factors including age, body mass index, maximum aerobic capacity, and body surface area were equal to 0.031, 0.145, - 0.064, and 0.106, respectively. The coefficients of main factors including dry temperature, wet temperature, globe temperature, wind speed, metabolism, and clothing thermal insulation were obtained as 0.739, 0.688, 0.765, 0.245, 0.482, and 0.383, respectively. These coefficients and normalized values of the factors were used to develop a novel index. The total score of the index was categorized into four levels by optimal cut-off points of 12.93, 16.48, and 18.87. Based on the results of regression analysis, this index justifies 77% of the tympanic temperature as a dependent variable (R2 = 0.77). Conclusions: In general, the results indicated that the novel index developed by the personal and main factors had proper validity in the prediction of thermal strain.
... for example, we were only able to use a tympanic thermometer to estimate body temperature instead of, for example, an ingestible telemetry pill sensor. although there are important limitations in assessing body temperature using noninvasive thermometers, Morán-Navarro et al. 32 reported that the tympanic thermometer used in the present study has reliably and validly estimated body temperature during exercise in the heat. ...
Article
Background: This crossover study's objective was to investigate whether a cooling intervention during simulated tennis match play in the heat could affect players' performance, physiology, perception of effort, and well-being. Methods: Eight competitive male tennis players performed two testing sessions of 45-minute simulated tennis match play on a hard court at 31.8 ± 2.1°C and 48.5 ± 9.6% relative humidity. During change-of-end breaks, the cooling interventions (COL) consisted of cold water ingestion (ad libitum) and an electric fan facing the players at a distance of 1 m combined with an ice-filled damp towel around the neck and on the thighs or no cooling (CON) were applied. Measures of performance, heart rate, blood lactate concentration, tympanic and local skin temperature, sweat loss, perceived exertion, and thermal sensation as well as ratings of recovery were recorded in both sessions. Results: Paired-samples t-tests showed no significant differences (p > 0.05) in any of the measures between COL and CON. Effect size (ES) calculations indicated moderate evidencethat COL was beneficial to local skin temperature (ES = -0.95) and thermal sensation (ES = -0.77). At the individual level, a positive response to COL was found in some players for heart rate, local skin temperature, thermal sensation, and ratings of recovery. Conclusions: A likely inability of COL to improve players' performance or reduce thermal strain during tennis match play in hot humid conditions was found at the group level. However, some players may be more likely to benefit from COL. Therefore, the use of COL should be individualized.
... IR measurements were shown to display high correlation with oral and forehead measurements in resting individuals (p < 0.01) (Basak et al., 2013). More variable results were obtained in the studies analyzing the effect of exercise in different environmental conditions (Gagnon et al., 2010;Bagley et al., 2011;Fogt et al., 2017;Harmanci et al., 2018;Morán-Navarro et al., 2019), where microclimate changes in the ear canal and changes in blood flow to the skin are known to impact measurements (Patel et al., 1996;Jensen et al., 2000;Casa et al., 2005;Kistemaker et al., 2006). Of note, tympanic measurements of T were not always compared to the "gold standard" site for core T (esophageal) (Strapazzon et al., 2014). ...
Article
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Technological advancements are opening the possibility of prolonged monitoring of physiological parameters under daily-life conditions, with potential applications in sport science and medicine, and in extreme environments. Among emerging wearable technologies, in-ear devices or hearables possess technical advantages for long-term monitoring, such as non-invasivity, unobtrusivity, good fixing, and reduced motion artifacts, as well as physiological advantages related to the proximity of the ear to the body trunk and the shared vasculature between the ear and the brain. The present scoping review was aimed at identifying and synthesizing the available evidence on the use and performance of in-ear monitoring of physiological parameters, with focus on applications in sport science, sport medicine, occupational medicine, and extreme environment settings. Pubmed, Scopus, and Web of Science electronic databases were systematically searched to identify studies conducted in the last 10 years and addressing the measurement of three main physiological parameters (temperature, heart rate, and oxygen saturation) in healthy subjects. Thirty-nine studies were identified, 24 performing temperature measurement, 12 studies on heart/pulse rate, and three studies on oxygen saturation. The collected evidence supports the premise of in-ear sensors as an innovative and unobtrusive way for physiological monitoring during daily-life and physical activity, but further research and technological advancement are necessary to ameliorate measurement accuracy especially in more challenging scenarios.
... Screeners may have missed infected individuals because other factors were influencing body temperature, including low ambient temperatures and recent administration of antipyretic medications (Hsiao, 2020). Sweating can also lead to inaccurate readings (Morán-Navarro et al., 2020). ...
... First, in order to perform cool first on EHS patients, accurate internal body temperature must be measured rectally to determine the need to cool and the end point of cooling at pre-hospital triage . However, the current common practice by the emergency medical technician is to use axillary or tympanic membrane temperature (Japanese Association for Acute Medicine, 2015), which provide inaccurate estimate of internal body temperature in exercising individuals (Casa et al., 2007a;Ganio et al., 2009;Taylor et al., 2014;Morán-Navarro et al., 2018). Axillary thermometry is an inexpensive method of internal body temperature assessment and is commonly used to assess pyrexia. ...
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Tokyo 2020 Summer Olympics are projected to experience environmental heat stress that surpasses the environmental conditions observed in the Atlanta (1996), Athens (2004), Beijing (2008), and Rio (2016) Summer Olympics. This raises particular concerns for athletes who will likely to be exposed to extreme heat during the competitions. Therefore, in mass-participation event during warm season, it is vital for the hosting organization to build preparedness and resilience against heat, including appropriate treatment, and management strategies for exertional heat stroke (EHS). However, despite the existing literature regarding the evidence-based management of EHS, rectal thermometry and whole-body cold-water immersion are not readily accepted by medical professionals outside of the sports, and military medicine professionals. Current Japanese medical standard is no exception in falling behind on evidence-based management of EHS. Therefore, the first aim of this paper is to elucidate the inconsistency between the standard of care provided in Japan for EHS and what has been accepted as the gold standard by the scientific literature. The second aim of this paper is to provide optimal EHS management strategies that should be implemented at the Tokyo 2020 Summer Olympics from organizational level to maximize the safety of athletes and to improve organizational resilience to heat. The risk of extreme heat is often neglected until a catastrophic incidence occurs. It is vital for the Japanese medical leadership and athletic communities to re-examine the current EHS management strategies and implement evidence-based countermeasure for EHS to expand the application of scientific knowledge.
... Data collected via ingestible sensors and tympanic thermometer were collapsed for data analysis and are referred to as T Core unless specified otherwise. Our decision to collapse the two measurements is in accordance with findings that indicate a negligible mean deviation between the two devices during exercise in the heat (Moran-Navarro et al., 2019). TS was collected using the 13-point McGinnis scale (Hollies, 1977). ...
Article
Objective To examine the effectiveness of hot water immersion (HWI) as a heat acclimation strategy in comparison to time and temperature matched, exercise-heat acclimation (EHA). Methods 8 males performed heat stress tests (HST) (45 min of cycling at 50% of VO2max in 40 °C, 40% RH) before and after heat acclimation sessions. Acclimation sessions were either three consecutive bouts of HWI (40 min of submersion at 40 °C) or EHA (40 min of cycling at 50% VO2max in 40 °C, 40% RH). Results Average change in tympanic temperature (TTympanic) was significantly higher following HWI (2.1 °C ± 0.4) compared to EHA (1.5 °C ± 0.4) (P < 0.05). Decreases in peak heart rate (HR) (HWI: −10 bpm ± 8; EHA: −6 ± 7), average HR (−7 bpm ± 6; −3 ± 4), and average core temperature (−0.4 °C ± 0.3; −0.2 ± 0.4) were evident following acclimation (P < 0.05), but not different between interventions (P > 0.05). Peak rate of perceived exertion (RPEPeak) decreased for HWI and EHA (P < 0.05). Peak thermal sensation (TSPeak) decreased following HWI (P < 0.05) but was not different between interventions (P > 0.05). Plasma volume increased in both intervention groups (HWI: 5.9% ± 5.1; EHA: 5.4% ± 3.7) but was not statistically different (P > 0.05). Conclusion HWI induced significantly greater thermal strain compared to EHA at equivalent temperatures during time-matched exposures. However, the greater degree of thermal strain did not result in between intervention differences for cardiovascular, thermoregulatory, or perceptual variables. Findings suggest three HWI sessions may be a potential means to lower HR, TCore, and perceptual strain during exercise in the heat.
... Consequently, tympanic or oral temperature is more often adopted in either a clinical or public setting. Despite high device accuracy, tympanic and sublingual (oral) temperature measurements are prone to ambient influences, such as air temperature and wind [54,55]. In the context of fever screening, these diagnostic tools are used to help confirm febrile status in individuals who screen positive for elevated temperature with NCIT. ...
Article
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The assessment of human internal/core temperature (T core) is relevant in many scientific disciplines , but also for public health authorities when attempting to identify individuals with fever. Direct assessment of T core is often invasive, impractical on a large scale, and typically requires close contact between the observer and the target subject. Non-contact infrared thermometry (NCIT) represents a practical solution in which T core can potentially be assessed from a safe distance and in mass screening scenarios, by measuring skin temperature at specific anatomical locations. However, the COVID-19 pandemic has clearly demonstrated that these devices are not being used correctly, despite expert guided specifications available in International Standard Organization (ISO) documents. In this review, we provide an overview of the most pertinent factors that should be considered by users of NCIT. This includes the most pertinent methodolo-gical and physiological factors, as well as an overview on the ability of NCIT to track human T core. For practical use, we provide a checklist based on relevant ISO standards which are simple to follow and should be consulted prior to using NCIT for assessment of human T core. Our intention is for users of NCIT to adopt this checklist, which may improve the performance of NCIT for its ability to track T core. ARTICLE HISTORY
... New trends in resistance and cardiopulmonary training methods appeal to more individualized regimes with a variety of exercises, stimuli and intensities, which are controlled by incorporating new technologies and monitoring tools. Current training methods are based on new approaches to monitoring exercise intensity (e.g., rate of force development, movement velocity), technical execution (e.g., biomechanics, electromyography), readiness (e.g., heart rate variability) and physiological responses (e.g., ventilation, lactate, core temperature, heart rate, muscle oxygen saturation) while providing biofeedback in real time, ensuring the accomplishment of targeted results [125][126][127][128][129][130]. Likewise, a number of portable devices, wearable tools and apps for physical activity and fitness are emerging, making remote control of the patients' evolution possible [131]. ...
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The coronavirus disease (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, is leading to unknown and unusual health conditions that are challenging to manage. Post-COVID-19 syndrome is one of those challenges, having become increasingly common as the pandemic evolves. The latest estimates suggest that 10 to 20% of the SARS-CoV-2 patients who undergo an acute symptomatic phase are experiencing effects of the disease beyond 12 weeks after diagnosis. Although research is beginning to examine this new condition, there are still serious concerns about the diagnostic identification, which limits the best therapeutic approach. Exercise programs and physical activity levels are well-known modulators of the clinical manifestations and prognosis in many chronic diseases. This narrative review summarizes the up-to-date evidence on post-COVID-19 syndrome to contribute to a better knowledge of the disease and explains how regular exercise may improve many of these symptoms and could reduce the long-term effects of COVID-19.
... Also, although when calculating PSI, rectal temperature is considered the gold standard measurement for core body temperature, ear canal temperature is a validated alternative that is more practical and less invasive (Amoateng-Adjepong et al., 1999;Heidari et al., 2018;Muir et al., 2001;Smitz et al., 2009). While ear temperature readings could be influenced by surrounding environmental conditions and temperature variations within the ear canal, it has been demonstrated that the digital thermometer device used in this study, Braun Thermoscan Exact Temp, can provide a valid core body temperature estimation during high physical activity in heat (Hamouti et al., 2010;Morán Navarro et al., 2019;Towey et al., 2017). ...
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Chronic kidney disease of unknown etiology (CKDu) is an epidemic that affects young agricultural workers in several warm regions of the world. However, there is a lack of monitoring of kidney issues in regions with extremely warm environments such as the Northwest of Mexico, a semi-arid region with a growing agricultural industry, where migrant and seasonal farm workers (MSFWs) travel to work in the fields. The objective of this study was to longitudinally assess kidney functioning of MSFWs in relation to pesticide exposure, heat stress and dehydration in a large-scale farm in Mexico. We enrolled 101 MSFWs, of whom 50 were randomly selected to work in an organic certified area and 51 were randomly selected to work in a conventional area. We also enrolled 50 office workers within the same region as a reference group. We collected urine and blood samples from all workers in addition to demographic, behavioral, and occupational characteristics. The physiological strain index (PSI) was used to estimate workers’ heat strain. Sampling was conducted at pre-harvest (March) and late in the harvest (July). Linear mixed models were built with the estimated glomerular filtration rate (eGFR) as the dependent variable. We found a significant decrease in kidney function in MSFWs compared to office workers. By the late harvest, one MSFW developed kidney disease, two MSFWs suffered a kidney injury, and 14 MSFWs were at risk of a kidney injury. We found that the eGFR in MSFWs decreased significantly from pre-harvest (125 ± 13.0 mL/min/1.73 m²) to late harvest (109 ± 13.6 mL/min/1.73 m²) (p < 0.001), while no significant change was observed in office workers. The eGFR was significantly lower in MSFWs who worked in the conventional field (101.2 ± 19.4 mL/min/1.73 m²) vs the organic field (110.9 ± 13.6 mL/min/1.73 m²) (p = 0.002). In our final model, we found that dehydration was associated with the decrease of eGFR. We also found an interaction between heat strain and job category, as a significant decline in eGFR by job category (conventional/organic MSFWs and office workers) was related to an increase in heat strain. This suggests that pesticide exposure needs to be considered in combination with heat stress and dehydration. This study provides valuable information on kidney function in MSFWs, and it shows the importance of early long-term monitoring in farm workers in other regions where CKDu has not been evaluated yet.
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Sensing and measuring meteorological and physiological parameters of humans, animals, and plants are necessary to understand the complex interactions that occur between atmospheric processes and the health of the living organisms. Advanced sensing technologies have provided both meteorological and biological data across increasingly vast spatial, spectral, temporal, and thematic scales. Information and communication technologies have reduced barriers to data dissemination, enabling the circulation of information across different jurisdictions and disciplines. Due to the advancement and rapid dissemination of these technologies, a review of the opportunities for sensing the health effects of weather and climate change is necessary. This paper provides such an overview by focusing on existing and emerging technologies and their opportunities and challenges for studying the health effects of weather and climate change on humans, animals, and plants.
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Special breathing exercises performed during warm-up lead to hypercapnia and stimulation of mechanisms leading to increased exercise performance, but the effect of a device that increases the respiratory dead space volume (ARDSv) during warm-up has not been studied. The purpose of this study was to investigate the effect of 10 min warm-up with ARDSv on performance, physiological and biochemical responses during sprint interval cycling exercise (SIE). During four laboratory visits at least 72 h apart, they completed: (1) an incremental exercise test (IET) on a cycloergometer, (2) a familiarization session, and cross-over SIE sessions conducted in random order on visits (3) and (4). During one of them, 1200 mL of ARDSv was used for breathing over a 10-min warm-up. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. Work capacity, cardiopulmonary parameters, body temperature, respiratory muscle strength, blood acid-base balance, lactate concentration, and rating of perceived exertion (RPE) were analyzed. After warm-up with ARDSv, PETCO2 was 45.0 ± 3.7 vs. 41.6 ± 2.5 (mm Hg) (p < 0.001). Body temperature was 0.6 (°C) higher after this form of warm-up (p < 0.05), bicarbonate concentration increased by 1.8 (mmol⋅L–1) (p < 0.01). As a result, work performed was 2.9% greater (p < 0.01) compared to the control condition. Respiratory muscle strength did not decreased. Warming up with added respiratory dead space volume mask prior to cycling SIE produces an ergogenic effect by increasing body temperature and buffering capacity.
Article
Purpose To investigate the effects of a very short-term acclimation protocol (VSTAP) on performance, physiological and perceptual responses to exercise in the heat. Methods 12 trained male cyclists (age 31.2 ± 7; weight 71.3 ± 7 kg, VO2max: 58.4 ± 3.7 mL/kg/min) randomly performed two Time to Exhaustion Tests (TTE) at 75% of normothermic peak power output (PPO), one in normothermia (N,18°C-50% RH) and one in the heat (H,35°C-50% RH), before and after a VSTAP intervention, consisting of 3 days–90 min exercise (10min at 30% of PPO+80 min at 50% of PPO) in H (≈4.5h of heat exposure). Performance time of TTEs and physiological and perceptual variables of both TTEs and training sessions (T1, T2 and T3) were evaluated. Results Magnitude Based Inferences (MBI) revealed 92/6/1% and 62/27/11% chances of positive/trivial/negative effects of VSTAP of improving performance in H (+17%) and in N (+9%), respectively. Heart Rate (HR) decreased from T1 to T3 (p < 0.001) and T2 to T3 (p < 0.001), whereas Tympanic Temperature (TyT) decreased from T1 to T2 (p = 0.047) and from T1 to T3 (p = 0.007). Furthermore, despite the increased tolerance to target Power Output (PO) throughout training sessions, RPE decreased from T1 to T3 (p = 0.032). Conclusions The VSTAP determined meaningful physiological (i.e. decreased HR and TyT) and perceptual (i.e. decreased RPE) adaptations to submaximal exercise. Furthermore, showing good chances to improve performance in the heat, it represents a valid acclimation strategy to be implemented when no longer acclimation period is possible. Finally, no cross-over effect of the VSTAP on performance in temperate conditions was detected.
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Aim To test whether infrared non-touch forehead thermometry (FNTT) obtains comparable temperature readings in adults compared with common, non-invasive thermometry methods such as axillary (DAT), oral (DOT) and infrared tympanic (ITT). Design A prospective, repeated-measures comparative diagnostic test study design was used for this study. Methods Data were collected from a convenience sample of 169 nursing students over 3 months (March 2019 to May 2019). Participants had their temperature measured once with each of the four thermometers. Agreement between thermometers was assessed using repeated-measures analysis of variance with Bonferroni post hoc testing. Results/findings One hundred and sixty-one participants were included in the final analysis. A repeated-measures ANOVA showed statistically significant differences between the four thermometer temperature readings. Post hoc pairwise comparisons with Bonferroni adjustment revealed infrared non-touch forehead thermometry demonstrated statistically significant higher mean temperatures compared with digital oral thermometry MD = 0.466℃ (95% CI, 0.357–0.576, p < .001) and digital axillary thermometry MD = 0.897℃ (95% CI, 0.752–1.043, p < .001), but not with infrared tympanic MD = 0.069℃ (95% CI, −0.025–0.162, p = .307). Conclusions This study found that infrared non-touch forehead thermometry consistently produced higher temperature readings in adults compared with other common forms of peripheral thermometry. Caution should be taken when using forehead non-touch thermometer readings interchangeably with digital oral and digital axillary readings unless corrections for bias are made. More research is needed into whether infrared non-touch forehead thermometry and infrared tympanic could be used interchangeably. Impact statement This study aimed to address whether non-touch forehead could be used interchangeably with other common forms of non-invasive thermometry. Our result revealed inconsistencies in temperature readings between the different thermometers. Consequently, healthcare professionals should exercise caution when monitoring temperature trends where readings have been taken by different types of peripheral thermometers. This study could impact healthcare clinicians responsible for the monitoring and recording of peripheral temperatures.
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Introduction / background / objectives Temperature screening (with infrared thermometers) in workplaces has proven to be controversial, creating discussions between Occupational health services teams, assuming as a “requirement” from workers and/ or Employers. This article intends to analyze the evidence of such as strategy. Methodology This is a descriptive literature review. The search for scientific sources was carried out using the PUBMED (Medline) databases during the month of July 2021, without time limitation, in Portuguese or English, with keywords “temperature screening” and “Covid-19”. Content Skin temperature, rather than core temperature, can be influenced by several factors; infrared thermometers does not appear to be reliable enough to detect or exclude fever, and fever is not a characteristic symptom of all infected from Covid-19. Thus, this unreliable proxy does not provide evidence to support its implementation in workplaces as an evidence-based measure. This strategy appears to lend more accountability to marketing and placebo than to evidence, helping workers and Employers feel better, but not doing much and potentially getting worse, by conveying a false sense of security. Conclusions Each workplace can determine its own preferences, depending on its particular epidemiological context, and for this reason there is no “right answer” on how Companies should approach this matter – the evidence on this topic is incomplete and the challenges posed by the pandemic are changing; however, in order to delineate more informed decisions, if we are to achieve, as a country, a fast economic recovery, employers will have to stop betting on measures that require resources, but which are placebos. KEY WORDS / EXPRESSIONS: temperature screening; Covid-19; Ocupacional Health.
Article
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Heart rate (HR) targets are commonly used to administer exercise intensity in sport and clinical practice. Yet, as exercise protracts, a time-dependent dissociation between HR and metabolism can lead to a mis-prescription of the intensity ingredient of the exercise dose. Purpose: we tested the hypothesis that a slow component of HR (i.e. scHR) occurs in all intensity domains, greater than the slow component of oxygen uptake (scV[Combining Dot Above]O2), and we developed an equation to predict it across exercise intensities. Method: 18 healthy, postmenopausal women (54 ± 4 years) performed on a cycle-ergometer: i) a ramp incremental test for thresholds and V[Combining Dot Above]O2max detection; ii) 30-min constant-work exercise at 40, 50, 60, 70, and 80 %V[Combining Dot Above]O2max for the measurement of scHR, scV[Combining Dot Above]O2, stroke volume (SV) and body temperature (T°). scHR and scV[Combining Dot Above]O2 were compared by two-way RM-ANOVA (intensity and variable); Pearson correlation was calculated between the slow component of all variables, relative intensity, and domain; scHR (b·min-2) was predicted with a linear model based on exercise intensity relative to the respiratory compensation point (RCP). Results: A positive scHR was present in all domains, twice the size of scV[Combining Dot Above]O2 (p < 0.001) and significantly correlated with the slow components of V[Combining Dot Above]O2 (r2 = 0.46), T° (r2 = 0.52) and with relative intensity (r2 = 0.66). A linear equation accurately predicts scHR based on %RCP (r2 = 0.66, SEE = 0.15). Discussion: A mismatch exists between the slow components of HR and metabolic intensity. Whenever exercise is prescribed based on HR, target values should be adjusted over time to grant that the desired metabolic stimulus is maintained throughout the exercise session.
Thesis
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The doctoral thesis presented in this document is structured in three different parts. The first part of the work is composed of studies I and II, where the validation work of two different workload cycling tools, “drive indoor trainer Cycleops Hammer” and “PowerTap P1 Pedals Power Meter “, is detailed. In both articles, randomized and counterbalanced incremental workload tests (100-500 W) were performed, at 70, 85 and 100 rev·min-1 cadence, with sitting and standing pedalling in 3 different Hammer unit cadences. Then, the results are compared against the values measured by a professional SRM crankset. In general terms, no significant differences were detected between the Hammer devices and the SRM, while strong intraclass correlation coefficients were observed (≥0.996; p=0.001), with low bias (-5,5 a 3,8), and high values of absolute reproducibility (CV<1,2%, SEM<2,1). The PowerTap P1 pedals showed strong correlation coefficients in a seated position (rho ≥ 0.987). They underestimated the power output obtained in a directly proportional way to the cadence, with an average error of 1.2%, 2.7%, 3.5% for 70, 85 and 100 rev∙min-1. However, they showed high absolute reproducibility values (150-500 W, CV = 2.3%, SEM <1.0W). These results prove that both are valid and reproducible devices to measure the power output in cycling, although caution should be exercised in the interpretation of the results due to the slight underestimation. The second part of the thesis is devoted to the study III, where the time to exhaustion (TTE) at the workloads related to the main events of the aerobic and anaerobic pathway in cycling were analysed in duplicate in a randomized and counterbalanced manner (Lactic anaerobic capacity (WAnTmean), the workload that elicit VO2max -MAP-, Second Ventilatory Threshold (VT2) and at Maximal Lactate Steady State (MLSS). TTE values were 00:28±00:07, 03:27±00:40, 11:03±04:45 and 76:35±12:27 mm:ss, respectively. Moderate between-subject reproducibility values were found (CV=22.2%,19.3%;43.1% and 16.3%), although low within-subject variability was found (CV=7.6%,6.9%;7.0% y 5.4%). According to these results, the %MAP where the physiological events were found seems to be a useful covariable to predict each TTE for training or competing purposes. Finally, in the third part of the work, the results of studies IV y V have been included. The validity of two different methods to estimate the cyclists’ workload at MLSS was evaluated. The first method was a 20 min time trial test (20TT), while the second method was a one-day incremental protocol including 4 steps of 10 minutes (1day_MLSS). The 20TT test absolute reproducibility, performed in duplicate, was very high (CV = -0.3±2.2%, ICC = 0.966, bias = 0.7±6.3 W). 95% of the mean 20TT workload overestimated the MLSS (bias 12.3±6.1W). In contrast, 91% of 20TT showed an accurate prediction of MLSS (bias 1.2±6.1 W), although the regression equation "MLSS (W) = 0.7489 * 20TT (W) + 43.203" showed even a better MLSS estimates (bias 0.1±5.0 W). Related to the 1day_MLSS test, the physiological steady state was determined as the highest workload that could be maintained with a [Lact] rise lower than 1mmol·L-1. No significant differences were detected between the MLSS (247±22 W) and the main construct of the test (DIF_10to10) (245±23 W), where the difference of [Lact] between minute 10 of two consecutive steps were considered, with high correlations (ICC = 0.960), low bias (2.2W), as well as high within-subject reliability (ICC = 0.846, CV = 0.4%, Bias = 2.2±6.4W). Both methods were revealed as valid predictors of the MLSS, significantly reducing the requirements needed to individually determine this specific intensity.
Article
Indoor stadium is an important place for physical exercise and sports practice, but few studies have considered the impact of indoor environment on exercise performance. Anaerobic exercise refers to exercise with high load intensity and instantaneous intensity. Many kinds of exercise performance are closely related to anaerobic exercise. Therefore, the purpose of this study was to examine the influence of temperature, relative humidity and CO2 concentration on anaerobic exercise performance. Sixteen healthy participants (21.5 ± 3.5 years) performed Wingate anaerobic test in 9 cases under the orthogonal experimental design. Temperature is a significant factor affecting peak power (p < 0.05) and average power (p < 0.05). The peak power at 22 °C and 25 °C is 5.4% and 5.1% higher than that at 28 °C, and the average power at 22 °C and 25 °C is 4.2% and 4.3% higher than that at 28 °C. Besides, temperature affected overall environmental satisfaction before and after exercise (p < 0.005, p < 0.005) as well as ear temperature in sedentary state and after warm-up exercise (p < 0.005, p < 0.005). The range of 22 °C–25 °C is closer to the neutral temperature, and it is suitable for anaerobic exercise. However, we did not find that changes in relative humidity and carbon dioxide concentration had an effect on anaerobic exercise performance.
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Background: Although the acquisition of heat acclimation (HA) is well-documented, less is known about HA decay (HAD) and heat re-acclimation (HRA). The available literature suggests 1 day of HA is lost following 2 days of HAD. Understanding this relationship has the potential to impact upon the manner in which athletes prepare for major competitions, as a HA regimen may be disruptive during final preparations (i.e., taper). Objective: The aim of this systematic review and meta-analysis was to determine the rate of HAD and HRA in three of the main physiological adaptations occurring during HA: heart rate (HR), core temperature (T c), and sweat rate (SR). Data sources: Data for this systematic review were retrieved from Scopus and critical review of the cited references. Study selection: Studies were included when they met the following criteria: HA, HAD, and HRA (when available) were quantified in terms of exposure and duration. HA had to be for at least 5 days and HAD for at least 7 days for longitudinal studies. HR, T c, or SR had to be monitored in human participants. Study appraisal: The level of bias in each study was assessed using the McMaster critical review form. Multiple linear regression techniques were used to determine the dependency of HAD in HR, T c, and SR from the number of HA and HAD days, daily HA exposure duration, and intensity. Results: Twelve studies met the criteria and were systematically reviewed. HAD was quantified as a percentage change relative to HA (0% = HA, 100% = unacclimated state). Adaptations in end-exercise HR decreased by 2.3% (P < 0.001) for every day of HAD. For end-exercise T c, the daily decrease was 2.6% (P < 0.01). The adaptations in T c during the HA period were more sustainable when the daily heat exposure duration was increased and heat exposure intensity decreased. The decay in SR was not related to the number of decay days. However, protracted HA-regimens seem to induce longer-lasting adaptations in SR. High heat exposure intensities during HA seem to evoke more sustained adaptations in SR than lower heat stress. Only eight studies investigated HRA. HRA was 8-12 times faster than HAD at inducing adaptations in HR and T c, but no differences could be established for SR. Limitations: The available studies lacked standardization in the protocols for HA and HAD. Conclusions: HAD and HRA differ considerably between physiological systems. Five or more HA days are sufficient to cause adaptations in HR and T c; however, extending the daily heat exposure duration enhances T c adaptations. For every decay day, ~ 2.5% of the adaptations in HR and T c are lost. For SR, longer HA periods are related to better adaptations. High heat exposure intensities seem beneficial for adaptations in SR, but not in T c. HRA induces adaptations in HR and T c at a faster rate than HA. HRA may thus provide a practical and less disruptive means of maintaining and optimizing HA prior to competition.
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An accurate measure of core body temperature is critical for monitoring individuals, groups and teams undertaking physical activity in situations of high heat stress or prolonged cold exposure. This study examined the range in systematic bias of ingestible temperature sensors compared to a certified and traceable reference thermometer. A total of 119 ingestible temperature sensors were immersed in a circulated water bath at five water temperatures (TEMP A: 35.12±0.60 °C, TEMP B: 37.33±0.56 °C, TEMP C: 39.48±0.73 °C, TEMP D: 41.58±0.97 °C, and TEMP E: 43.47±1.07 °C) along with a certified traceable reference thermometer. Thirteen sensors (10.9%) demonstrated a systematic bias greater than ±0.1 °C, of which 4 (3.3%) were greater than 0.06±0.24 °C. Limits of agreement (95%) indicated that systematic bias would likely fall in the range of -0.14 to 0.26 °C, highlighting that it is possible for temperatures measured between sensors to differ by more than 0.4 °C. The proportion of sensors with systematic bias greater than ±0.1 °C (10.9%) confirms that ingestible temperature sensors require correction to ensure their accuracy. An individualised linear correction achieved a mean systematic bias of 0.00 °C, and limits of agreement (95%) to 0.00 to 0.00 °C, with 100% of sensors achieving ±0.1 °C accuracy. Alternatively, a generalised linear function (Corrected Temperature (°C) = 1.00375 x Sensor Temperature (°C) - 0.205549), produced as the average slope and intercept of a sub-set of 52 sensors and excluding sensors with accuracy outside ±0.5 °C, reduced the systematic bias to less than ±0.1 °C in 98.4% of the remaining sensors (n = 64). In conclusion, these data show that using an uncalibrated ingestible temperature sensor may provide inaccurate data that still appears to be statistically, physiologically, and clinically meaningful. Correction of sensor temperature to a reference thermometer by linear function eliminates this systematic bias (individualised functions) or ensures systematic bias is within ±0.1 °C in 98% of the sensors (generalised function).
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Purpose The purpose of this study was to determine, i) the reliability of blood lactate and ventilatory-based thresholds, ii) the lactate threshold that corresponds with each ventilatory threshold (VT1 and VT2) and with maximal lactate steady state test (MLSS) as a proxy of cycling performance. Methods Fourteen aerobically-trained male cyclists (V˙O2max 62.1±4.6 ml·kg⁻¹·min⁻¹) performed two graded exercise tests (50 W warm-up followed by 25 W·min⁻¹) to exhaustion. Blood lactate, V˙O2 and V˙CO2 data were collected at every stage. Workloads at VT1 (rise in V˙E/V˙O2;) and VT2 (rise in V˙E/V˙CO2) were compared with workloads at lactate thresholds. Several continuous tests were needed to detect the MLSS workload. Agreement and differences among tests were assessed with ANOVA, ICC and Bland-Altman. Reliability of each test was evaluated using ICC, CV and Bland-Altman plots. Results Workloads at lactate threshold (LT) and LT+2.0 mMol·L⁻¹ matched the ones for VT1 and VT2, respectively (p = 0.147 and 0.539; r = 0.72 and 0.80; Bias = -13.6 and 2.8, respectively). Furthermore, workload at LT+0.5 mMol·L⁻¹ coincided with MLSS workload (p = 0.449; r = 0.78; Bias = -4.5). Lactate threshold tests had high reliability (CV = 3.4–3.7%; r = 0.85–0.89; Bias = -2.1–3.0) except for DMAX method (CV = 10.3%; r = 0.57; Bias = 15.4). Ventilatory thresholds show high reliability (CV = 1.6%–3.5%; r = 0.90–0.96; Bias = -1.8–2.9) except for RER = 1 and V-Slope (CV = 5.0–6.4%; r = 0.79; Bias = -5.6–12.4). Conclusions Lactate threshold tests can be a valid and reliable alternative to ventilatory thresholds to identify the workloads at the transition from aerobic to anaerobic metabolism.
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Military activities in hot environments pose two competing demands: the requirement to perform realistic training to develop operational capability with the necessity to protect armed forces personnel against heat-related illness. To ascertain whether work duration limits for protection against heat-related illness restrict military activities, this study examined the heat strain and risks of heat-related illness when conducting a military activity above the prescribed work duration limits. Thirty-seven soldiers conducted a march (10 km; ˜5.5 km·h−1) carrying 41.8±3.6 kg of equipment in 23.1±1.8°C wet-bulb globe temperature. Body core temperature was recorded throughout and upon completion, or withdrawal, participants rated their severity of heat-related symptoms. Twenty-three soldiers completed the march in 107±6.4 min (Completers); nine were symptomatic for heat exhaustion, withdrawing after 71.6 ±10.1 min (Symptomatic); and five were removed for body core temperature above 39.0°C (Hyperthermic) after 58.4±4.5 min. Body core temperature was significantly higher in the Hyperthermic (39.03±0.26°C), than Symptomatic (38.34±0.44°C; P=0.007) and Completers (37.94±0.37°C; P<0.001) after 50 min. Heat-related symptom severity was significantly higher among Symptomatic (28.4±11.8) compared to Completers (15.0±9.8, P=0.006) and Hyperthermic (13.0±9.6, P=0.029). The force protection provided by work duration limits may be preventing the majority of personnel from conducting activities in hot environments, thereby constraining a commander's mandate to develop an optimised military force. The dissociation between heat-related symptoms and body core temperature elevation suggests that the physiological mechanisms underpinning exhaustion during exertional heat stress should be re-examined to determine the most appropriate physiological criteria for prescribing work duration limits.
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This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses during exercise-heat acclimation. The cardiovascular system is well recognized as an important contributor to exercise-heat acclimation that acts to minimize physiological strain, reduce the risk of serious heat illness and better sustain exercise capacity. The upright posture adopted by humans during most physical activities and the large skin surface area contribute to the circulatory and blood pressure regulation challenge of simultaneously supporting skeletal muscle blood flow and dissipating heat via increased skin blood flow and sweat secretion during exercise-heat stress. Although it was traditionally held that cardiac output increased during exercise-heat stress to primarily support elevated skin blood flow requirements, recent evidence suggests that temperature-sensitive mechanisms may also mediate an elevation in skeletal muscle blood flow. The cardiovascular adaptations supporting this challenge include an increase in total body water, plasma volume expansion, better sustainment and/or elevation of stroke volume, reduction in heart rate, improvement in ventricular filling and myocardial efficiency, and enhanced skin blood flow and sweating responses. The magnitude of these adaptations is variable and dependent on several factors such as exercise intensity, duration of exposure, frequency and total number of exposures, as well as the environmental conditions (i.e. dry or humid heat) in which acclimation occurs.
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Objective: To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. Background: Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. Recommendations: Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.
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In a contemporary clinical laboratory it is very common to have to assess the agreement between two quantitative methods of measurement. The correct statistical approach to assess this degree of agreement is not obvious. Correlation and regression studies are frequently proposed. However, correlation studies the relationship between one variable and another, not the differences, and it is not recommended as a method for assessing the comparability between methods. In 1983 Altman and Bland (B&A) proposed an alternative analysis, based on the quantification of the agreement between two quantitative measurements by studying the mean difference and constructing limits of agreement. The B&A plot analysis is a simple way to evaluate a bias between the mean differences, and to estimate an agreement interval, within which 95% of the differences of the second method, compared to the first one, fall. Data can be analyzed both as unit differences plot and as percentage differences plot. The B&A plot method only defines the intervals of agreements, it does not say whether those limits are acceptable or not. Acceptable limits must be defined a priori, based on clinical necessity, biological considerations or other goals. The aim of this article is to provide guidance on the use and interpretation of Bland Altman analysis in method comparison studies.
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Skin temperature is an important physiological measure that can reflect the presence of illness and injury as well as provide insight into the localised interactions between the body and the environment. The aim of this systematic review was to analyse the agreement between conductive and infrared means of assessing skin temperature which are commonly employed in in clinical, occupational, sports medicine, public health and research settings. Full-text eligibility was determined independently by two reviewers. Studies meeting the following criteria were included in the review: (1) the literature was written in English, (2) participants were human (in vivo), (3) skin surface temperature was assessed at the same site, (4) with at least two commercially available devices employed—one conductive and one infrared—and (5) had skin temperature data reported in the study. A computerised search of four electronic databases, using a combination of 21 keywords, and citation tracking was performed in January 2015. A total of 8,602 were returned. Methodology quality was assessed by two authors independently, using the Cochrane risk of bias tool. A total of 16 articles (n = 245) met the inclusion criteria. Devices are classified to be in agreement if they met the clinically meaningful recommendations of mean differences within ±0.5 °C and limits of agreement of ±1.0 °C. Twelve of the included studies found mean differences greater than ±0.5 °C between conductive and infrared devices. In the presence of external stimulus (e.g. exercise and/or heat) five studies found exacerbated measurement differences between conductive and infrared devices. This is the first review that has attempted to investigate presence of any systemic bias between infrared and conductive measures by collectively evaluating the current evidence base. There was also a consistently high risk of bias across the studies, in terms of sample size, random sequence generation, allocation concealment, blinding and incomplete outcome data. This systematic review questions the suitability of using infrared cameras in stable, resting, laboratory conditions. Furthermore, both infrared cameras and thermometers in the presence of sweat and environmental heat demonstrate poor agreement when compared to conductive devices. These findings have implications for clinical, occupational, public health, sports science and research fields.
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Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimizing the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events for hydration and body cooling opportunities when competitions are held in the heat. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Skin temperature assessment has historically been undertaken with conductive devices affixed to the skin. With the development of technology, infrared devices are increasingly utilised in the measurement of skin temperature. Therefore, our purpose was to evaluate the agreement between four skin temperature devices at rest, during exercise in the heat, and recovery. Mean skin temperature ([Formula: see text]) was assessed in thirty healthy males during 30 min rest (24.0 ± 1.2°C, 56 ± 8%), 30 min cycle in the heat (38.0 ± 0.5°C, 41 ± 2%), and 45 min recovery (24.0 ± 1.3°C, 56 ± 9%). [Formula: see text] was assessed at four sites using two conductive devices (thermistors, iButtons) and two infrared devices (infrared thermometer, infrared camera). Bland-Altman plots demonstrated mean bias ± limits of agreement between the thermistors and iButtons as follows (rest, exercise, recovery): -0.01 ± 0.04, 0.26 ± 0.85, -0.37 ± 0.98°C; thermistors and infrared thermometer: 0.34 ± 0.44, -0.44 ± 1.23, -1.04 ± 1.75°C; thermistors and infrared camera (rest, recovery): 0.83 ± 0.77, 1.88 ± 1.87°C. Pairwise comparisons of [Formula: see text] found significant differences (p < 0.05) between thermistors and both infrared devices during resting conditions, and significant differences between the thermistors and all other devices tested during exercise in the heat and recovery. These results indicate poor agreement between conductive and infrared devices at rest, during exercise in the heat, and subsequent recovery. Infrared devices may not be suitable for monitoring [Formula: see text] in the presence of, or following, metabolic and environmental induced heat stress.
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To determine whether the ergogenic effects of caffeine ingestion on neuromuscular performance are similar when ingestion takes place in the morning and in the afternoon. Double blind, cross-over, randomized, placebo controlled design. Thirteen resistance-trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75% and 90% 1RM), at maximal velocity. Trials took place 60min after ingesting either 6mgkg(-1) of caffeine or placebo. Two trials took place in the morning (AMPLAC and AMCAFF) and two in the afternoon (PMPLAC and PMCAFF), all separated by 36-48h. Tympanic temperature, plasma caffeine concentration and side-effects were measured. Plasma caffeine increased similarly during AMCAFF and PMCAFF. Tympanic temperature was lower in the mornings without caffeine effects (36.7±0.4 vs. 37.0±0.5°C for AM vs. PM; p<0.05). AMCAFF increased propulsive velocity above AMPLAC to levels similar to those found in the PM trials for the 25%, 50%, 75% 1RM loads in the SQ exercise (5.4-8.1%; p<0.05). However, in the PM trials, caffeine ingestion did not improve propulsive velocity at any load during BP or SQ. The negative side effects of caffeine were more prevalent in the afternoon trials (13 vs. 26%). The ingestion of a moderate dose of caffeine counteracts the muscle contraction velocity declines observed in the morning against a wide range of loads. Caffeine effects are more evident in the lower body musculature. Evening caffeine ingestion not only has little effect on neuromuscular performance, but increases the rate of negative side-effects reported.
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In Olympic combat sports, weight cutting is a common practice aimed to take advantage of competing in weight divisions below the athlete's normal weight. Fluid and food restriction in combination with dehydration (sauna and/or exercise induced profuse sweating) are common weight cut methods. However, the resultant hypohydration could adversely affect health and performance outcomes. The aim of this study is to determine which of the routinely used non-invasive measures of dehydration best track urine osmolality, the gold standard non-invasive test. Immediately prior to the official weigh-in of three National Championships, the hydration status of 345 athletes of Olympic combat sports (i.e., taekwondo, boxing and wrestling) was determined using five separate techniques: i) urine osmolality (UOSM), ii) urine specific gravity (USG), iii) urine color (UCOL), iv) bioelectrical impedance analysis (BIA), and v) thirst perception scale (TPS). All techniques were correlated with UOSM divided into three groups: euhydrated (G1; UOSM 250-700 mOsm·kg H2O-1), dehydrated (G2; UOSM 701-1080 mOsm·kg H2O-1), and severely dehydrated (G3; UOSM 1081-1500 mOsm·kg H2O-1). We found a positive high correlation between the UOSM and USG (r = 0.89: p = 0.000), although this relationship lost strength as dehydration increased (G1 r = 0.92; G2 r = 0.73; and G3 r = 0.65; p = 0.000). UCOL showed a moderate although significant correlation when considering the whole sample (r = 0.743: p = 0.000) and G1 (r = 0.702: p = 0.000) but low correlation for the two dehydrated groups (r = 0.498-0.398). TPS and BIA showed very low correlation sizes for all groups assessed. In a wide range of pre-competitive hydration status (UOSM 250-1500 mOsm·kg H2O-1), USG is highly associated with UOSM while being a more affordable and easy to use technique. UCOL is a suitable tool when USG is not available. However, BIA or TPS are not sensitive enough to detect hypohydration at official weight-in before an Olympic combat championship.
Article
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Measuring skin temperature (TSK) provides important information about the complex thermal control system and could be interesting when carrying out studies about thermoregulation. The most common method to record TSK involves thermocouples at specific locations; however, the use of infrared thermal imaging (IRT) has increased. The two methods use different physical processes to measure TSK, and each has advantages and disadvantages. Therefore, the objective of this study was to compare the mean skin temperature (MTSK) measurements using thermocouples and IRT in three different situations: pre-exercise, exercise and post-exercise. Analysis of the residual scores in Bland-Altman plots showed poor agreement between the MTSK obtained using thermocouples and those using IRT. The averaged error was -0.75 °C during pre-exercise, 1.22 °C during exercise and -1.16 °C during post-exercise, and the reliability between the methods was low in the pre- (ICC = 0.75 [0.12 to 0.93]), during (ICC = 0.49 [-0.80 to 0.85]) and post-exercise (ICC = 0.35 [-1.22 to 0.81] conditions. Thus, there is poor correlation between the values of MTSK measured by thermocouples and IRT pre-exercise, exercise and post-exercise, and low reliability between the two forms of measurement.
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Background During investigation and diagnosis of patients, accurate temperature measurement is of great importance. The advantages of tympanic membrane thermometry are speed (temperature reading available within seconds), safety, and ease of use. The aim of this study was to compare the accuracy of infrared tympanic thermometers in comparison to mercury thermometers in measurement of body temperature. Methods Axillary and tympanic temperature was measured simultaneously in consecutive patients using mercury glass and infrared tympanic thermometers at Omdurman Hospital, Sudan during October 2012. Results In total, temperature was measured in 174 patients, 95 of whom (54.6%) were male. The mean (SD) patient age and weight was 33.18 (25.07) years and 52.13 (69.85) kg. There was no significant difference in mean (SD) temperature measurement between mercury and infrared tympanic membrane thermometers, 37.29°C (0.91) versus 37.38°C (0.95), P = 0.373, respectively. There was a significant positive correlation between axillary and tympanic body temperature measurements (r = 0.697, P < 0.001). The mean difference between the two readings (with limits of agreements) was - 0.093 (−0.20; 0.02) °C. Conclusion In this study, tympanic membrane thermometry is as reliable and accurate as axillary mercury glass thermometry. Thus, tympanic thermometry can be used in clinical practice, especially in the emergency setting, where ease of use and speed of obtaining the temperature reading are important.
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Heat dissipation during sport exercise is an important physiological mechanism that may influence athletic performance. Our aim was to test the hypothesis that differences exist in the dynamics of exercise-associated skin temperature changes between trained and untrained subjects. We investigated thermoregulation of a local muscle area (muscle-tendon unit) involved in a localized steady-load exercise (standing heels raise) using infrared thermography. Seven trained female subjects and seven untrained female controls were studied. Each subject performed standing heels raise exercise for 2 min. Thermal images were recorded prior to exercise (1 min), during exercise (2 min), and after exercise (7 min). The analysis of thermal images provided the skin temperature time course, which was characterized by a set of descriptive parameters. Two-way ANOVA for repeated measures detected a significant interaction (p = 0.03) between group and time, thus indicating that athletic subjects increased their skin temperature differently with respect to untrained subjects. This was confirmed by comparing the parameters describing the speed of rise of skin temperature. It was found that trained subjects responded to exercise more quickly than untrained controls (p < 0.05). In conclusion, physical training improves the ability to rapidly elevate skin temperature in response to a localized exercise in female subjects.
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Medical infrared thermography (MIT) is used for analyzing physiological functions related to skin temperature. Technological advances have made MIT a reliable medical measurement tool. This paper provides an overview of MIT's technical requirements and usefulness in sports medicine, with a special focus on overuse and traumatic knee injuries. Case studies are used to illustrate the clinical applicability and limitations of MIT. It is concluded that MIT is a non-invasive, non-radiating, low cost detection tool which should be applied for pre-scanning athletes in sports medicine.
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Clinical measurements such as temperature are commonly used for screening and diagnosis. However, little is known about the reliability of specific thermometers or measurement techniques. This study sought to define normal tympanic temperature and to assess the reliability of tympanic thermometry. Using a cross-sectional survey design, 244 children aged between one and six years at a paediatric outpatients department had their temperature recorded three times in each ear using a Braun Thermoscan thermometer. Mean temperature was 36.65 degrees C with an overall repeatability statistic of 0.78 degrees C, 0.55 degrees C in the left ear and 0.64 degrees C in the right. The level of measurement error did not increase with temperature, or differ between ages. Environmental temperature had only a moderate effect on temperature, and there was no effect from environmental humidity. Tympanic thermometry using the Braun ThermoScan is a reliable method of temperature measurement, with a temperature change of approximately 0.6 degrees C being significant. Although the effects of environmental conditions were slight, these were in temperate conditions. This study should be repeated for other models of thermometer.
Article
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When assessing exercise hyperthermia outdoors, the validity of certain commonly used body temperature measuring devices has been questioned. A controlled laboratory environment is generally less influenced by environmental factors (eg, ambient temperature, solar radiation, wind) than an outdoor setting. The validity of these temperature measuring devices in a controlled environment may be more acceptable. To assess the validity and reliability of commonly used temperature devices compared with rectal temperature in individuals exercising in a controlled, high environmental temperature indoor setting and then resting in a cool environment. Time series study. Laboratory environmental chamber (temperature = 36.4 +/- 1.2 degrees C [97.5 +/- 2.16 degrees F], relative humidity = 52%) and cool laboratory (temperature = approximately 23.3 degrees C [74.0 degrees F], relative humidity = 40%). Fifteen males and 10 females. Rectal, gastrointestinal, forehead, oral, aural, temporal, and axillary temperatures were measured with commonly used temperature devices. Temperature was measured before and 20 minutes after entering the environmental chamber, every 30 minutes during a 90-minute treadmill walk in the heat, and every 20 minutes during a 60-minute rest in mild conditions. Device validity and reliability were assessed with various statistical measures to compare the measurements using each device with rectal temperature. A device was considered invalid if the mean bias (average difference between rectal and device temperatures) was more than +/-0.27 degrees C (+/-0.50 degrees F). Measured temperature from each device (mean and across time). The following devices provided invalid estimates of rectal temperature: forehead sticker (0.29 degrees C [0.52 degrees F]), oral temperature using an inexpensive device (-1.13 degrees C [-2.03 degrees F]), temporal temperature measured according to the instruction manual (-0.87 degrees C [-1.56 degrees F]), temporal temperature using a modified technique (-0.63 degrees C [-1.13 degrees F]), oral temperature using an expensive device (-0.86 degrees C, [-1.55 degrees F]), aural temperature (-0.67 degrees C, [-1.20 degrees F]), axillary temperature using an inexpensive device (-1.25 degrees C, [-2.24 degrees F]), and axillary temperature using an expensive device (-0.94 degrees F [-1.70 degrees F]). Measurement of intestinal temperature (mean bias of -0.02 degrees C [-0.03 degrees F]) was the only device considered valid. Devices measured in succession (intestinal, forehead, temporal, and aural) showed acceptable reliability (all had a mean bias = 0.09 degrees C [0.16 degrees F] and r >or= 0.94]). Even during laboratory exercise in a controlled environment, devices used to measure forehead, temporal, oral, aural, and axillary body sites did not provide valid estimates of rectal temperature. Only intestinal temperature measurement met the criterion. Therefore, we recommend that rectal or intestinal temperature be used to assess hyperthermia in individuals exercising indoors in the heat.
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This Position Stand provides guidance on fluid replacement to sustain appropriate hydration of individuals performing physical activity. The goal of prehydrating is to start the activity euhydrated and with normal plasma electrolyte levels. Prehydrating with beverages, in addition to normal meals and fluid intake, should be initiated when needed at least several hours before the activity to enable fluid absorption and allow urine output to return to normal levels. The goal of drinking during exercise is to prevent excessive (>2% body weight loss from water deficit) dehydration and excessive changes in electrolyte balance to avert compromised performance. Because there is considerable variability in sweating rates and sweat electrolyte content between individuals, customized fluid replacement programs are recommended. Individual sweat rates can be estimated by measuring body weight before and after exercise. During exercise, consuming beverages containing electrolytes and carbohydrates can provide benefits over water alone under certain circumstances. After exercise, the goal is to replace any fluid electrolyte deficit. The speed with which rehydration is needed and the magnitude of fluid electrolyte deficits will determine if an aggressive replacement program is merited.
Article
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Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings. To assess the validity of commonly used temperature devices at various body sites during outdoor exercise in the heat. Observational field study. Outdoor athletic facilities. Fifteen men and 10 women (age = 26.5 +/- 5.3 years, height = 174.3 +/- 11.1 cm, mass = 72.73 +/- 15.95 kg, body fat = 16.2 +/- 5.5%). We simultaneously tested inexpensive and expensive devices orally and in the axillary region, along with measures of aural, gastrointestinal, forehead, temporal, and rectal temperatures. Temporal temperature was measured according to the instruction manual and a modified method observed in medical tents at local road races. We also measured forehead temperatures directly on the athletic field (other measures occurred in a covered pavilion) where solar radiation was greater. Rectal temperature was the criterion standard used to assess the validity of all other devices. Subjects' temperatures were measured before exercise, every 60 minutes during 180 minutes of exercise, and every 20 minutes for 60 minutes of postexercise recovery. Temperature devices were considered invalid if the mean bias (average difference between rectal temperature and device temperature) was greater than +/-0.27 degrees C (+/-0.5 degrees F). Temperature from each device at each site and time point. Mean bias for the following temperatures was greater than the allowed limit of +/-0.27 degrees C (+/-0.5 degrees F): temperature obtained via expensive oral device (-1.20 degrees C [-2.17 degrees F]), inexpensive oral device (-1.67 degrees C [-3.00 degrees F]), expensive axillary device (-2.58 degrees C [-4.65 degrees F]), inexpensive axillary device (-2.07 degrees C [-3.73 degrees F]), aural method (-1.00 degrees C [-1.80 degrees F]), temporal method according to instruction manual (-1.46 degrees C [-2.64 degrees F]), modified temporal method (-1.36 degrees C [-2.44 degrees F]), and forehead temperature on the athletic field (0.60 degrees C [1.08 degrees F]). Mean bias for gastrointestinal temperature (-0.19 degrees C [-0.34 degrees F]) and forehead temperature in the pavillion (-0.14 degrees C [-0.25 degrees F]) was less than the allowed limit of +/-0.27 degrees C (+/-0.5 degrees F). Forehead temperature depended on the setting in which it was measured and showed greater variation than other temperatures. Compared with rectal temperature (the criterion standard), gastrointestinal temperature was the only measurement that accurately assessed core body temperature. Oral, axillary, aural, temporal, and field forehead temperatures were significantly different from rectal temperature and, therefore, are considered invalid for assessing hyperthermia in individuals exercising outdoors in the heat.
Article
Objective To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. Background Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment of, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. Recommendations Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.
Book
This book addresses the application of infrared thermography in sports, examining the main benefits of this non-invasive, non-radiating and low-cost technique. Aspects covered include the detection of injuries in sports medicine, the assessment of sports performance due to the existing link between physical fitness and thermoregulation and the analysis of heat transfer for sports garments and sports equipment. Although infrared thermography is broadly considered to be a fast and easy-to-use tool, the ability to deliver accurate and repeatable measurements is an important consideration. Furthermore, it is important to be familiar with the latest sports studies published on this technique to understand its potential and limitations. Accordingly, this book establishes a vital link between laboratory tests and the sports field.
Chapter
Infrared thermography presents some important advantages in the determination of skin temperature, as it is a safe, non-invasive and non-contact technique with wide applications in the field of sports sciences. Like many others techniques, valid measurement in thermography requires following strict methodological steps from data acquisition to analyses and interpretation. In this chapter, we discuss the methodological aspects that must be taken into account when acquiring thermic images, along with some practical examples and recommendations based on the current literature.
Article
The aim of the present study was to compare infrared thermography and thermal contact sensors for measuring skin temperature during cycling in a moderate environment. Fourteen cyclists performed a 45-min cycling test at 50% of peak power output. Skin temperatures were simultaneously recorded by infrared thermography and thermal contact sensors before and immediately after cycling activity as well as after 10 min cooling-down, representing different skin wetness and blood perfusion states. Additionally, surface temperature during well controlled dry and wet heat exchange (avoiding thermoregulatory responses) using a hot plate system was assessed by infrared thermography and thermal contact sensors. In human trials, the inter-method correlation coefficient was high when measured before cycling (r = 0.92) whereas it was reduced immediately after the cycling (r = 0.82) and after the cooling-down phase (r = 0.59). Immediately after cycling, infrared thermography provided lower temperature values than thermal contact sensors whereas it presented higher temperatures after the cooling-down phase. Comparable results as in human trials were observed for hot plate tests in dry and wet states. Results support the application of infrared thermography for measuring skin temperature in exercise scenarios where perspiration does not form a water film.
Article
Climatic injuries, including hypothermia, hyperthermia and heat stroke, are common in many sports activities. Body core temperature (Tc) measurement for the sportsperson can influence individual performance and may help to prevent injuries. Monitoring internal body Tc accurately requires invasive methods of measurement. The mercury thermometer, most commonly used to measure oral temperature (Toral), has been almost exclusively the only instrument for measuring Tc since the 18th century. Rectal (Tre) and oesophageal temperatures (Toes) have been the most preferred measurement sites employed in thermoregulatory investigations. However, these measurement sites (Tre, Toes, Toral), and the methods used to measure Tc at these sites, are not convenient. Toral measurements are not always possible or accurate. Toes is undesirable because of the difficulty of inserting the thermistor, irritation to nasal passages and general subject discomfort. Tre is not suitable under many circumstances as it is labour intensive and has a prolonged response time. However, Tre remains the most accurately available method for monitoring Tc in thermal illness that occurs during sports activities. In addition, Tre and Toes require wire connections between the thermistor and the monitoring device. The purpose of this paper is to review the various existing methods of Tc measurements in order to focus on the breakthrough needed for a simple, noninvasive, universally used device for Tc measurement which is essential for preventing climatic injuries during sports events.
Article
Thermography for scientific research and practical purposes requires a series of procedures to obtain images that should be standardized; one of the most important is the time required for acclimatization in the controlled environment. Thus, the objective of this study was to identify the appropriate acclimatization time in rest to reach a thermal balance on young people skin. Forty-four subjects participated in the study, 18 men (22.3 ± 3.1 years) and 26 women (21.7 ± 2.5 years). Thermographic images were collected using a thermal imager (Fluke ®), totaling 44 images over a period of 20 minutes. The skin temperature (TSK) was measured at the point of examination which included the 0 minute, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20. The body regions of interest (ROI) analyzed included the hands, forearms, arms, thighs, legs, chest and abdomen. We used the Friedman test with post hoc Dunn’s in order to establish the time at rest required to obtain a TSK balance and the Mann-Whitney test was used to compare age, BMI, body fat percentage and temperature variations between men and women, considering always a significance level of p<0.05. Results showed that women had significantly higher temperature variations than men (p<0.01) along the time. In men, only the body region of the abdomen obtained a significant variance (p<0.05) on the analyzed period, both in the anterior and posterior part. In women, the anterior abdomen and thighs, and the posterior part of the hands, forearms and abdomen showed significant differences (p<0.05). Based on our results, it can be concluded that the time in rest condition required reaching a TSK balance in young men and women is variable, but for whole body analysis it is recommended at least 10 minutes for both sexes.
Article
Infrared thermoimaging is one of the options for object temperature analysis. Infrared thermoimaging is unique due to the non-contact principle of measurement. So it is often used in medicine and for scientific experimental measurements. The presented work aims to determine whether the measurement results could be influenced by topical treatment of the hand surface by various substances. The authors attempted to determine whether the emissivity can be neglected or not in situations of topical application of substances such as ultrasound gel, ointment, disinfection, etc. The results of experiments showed that the value of surface temperature is more or less distorted by the topically applied substance. Our findings demonstrate the effect of emissivity of applied substances on resulting temperature and showed the necessity to integrate the emissivity into calculation of the final surface temperature. Infrared thermoimaging can be an appropriate method for determining the temperature of organisms, if this is understood as the surface temperature, and the surrounding environment and its temperature is taken into account.
Article
The direct measurement of the temperature of the human body core, while being of great significance for the evaluation of patient health, is inconvenient. This realization has motivated attempts to measure the core temperature indirectly, for the most part at locations which do not require invasion of the body. In the investigation described here, a new approach to noninvasive measurement of the core temperature is set forth. The site of the proposed measurement is on the forehead where the anatomy is relatively uniform amongst individuals and also well established to be modeled accurately. The approach described here consists of simple hardware and a logic-based and customized control algorithm.The connection between the core temperature, the sensor temperature, and the temperature of a sensor-system heater was determined by numerical simulations of the heat transfer in the tissue bed fronted by the forehead skin and backed by the frontal bone. For heat transfer through each tissue layer in the tissue bed, the bioheat equation was employed, while for a resistance element in the sensing system, the Fourier heat conduction equation was used. These were solved in the transient mode. The controller read the temperatures of the core, the sensor, and the ambient, and the algorithm instructed the sensor-system heater to obtain a specific temperature value. The iterative use of the control algorithm resulted in near-equality of the sensor and core temperatures.An optimization routine performed operations needed to find the best performing sensor system. After optimization, that system is capable of yielding core temperature results that are approximately in error by 0.2 °C.A model problem was formulated to assess the capabilities of the sensing system to follow a time-varying core temperature. It was found that for core temperatures that varied by 0.05 °C per minute, the sensor followed the core within 0.2 °C or better.
Article
Core temperature measurement with an ingestible telemetry pill has been scarcely investigated during extreme rates of temperature change, induced by short high-intensity exercise in the heat. Therefore, nine participants performed a protocol of rest, (sub)maximal cycling and recovery at 30 °C. The pill temperature (T(pill)) was compared with the rectal temperature (T(re)) and esophageal temperature (T(es)). T(pill) corresponded well to T(re) during the entire trial, but deviated considerably from T(es) during the exercise and recovery periods. During maximal exercise, the average ΔT(pill)-T(re) and ΔT(pill)-T(es) were 0.13 ± 0.26 and -0.57 ± 0.53 °C, respectively. The response time from the start of exercise, the rate of change during exercise and the peak temperature were similar for T(pill) and T(re.) T(es) responded 5 min earlier, increased more than twice as fast and its peak value was 0.42 ± 0.46 °C higher than T(pill). In conclusion, also during considerable temperature changes at a very high rate, T(pill) is still a representative of T(re). The extent of the deviation in the pattern and peak values between T(pill) and T(es) (up to >1 °C) strengthens the assumption that T(pill) is unsuited to evaluate central blood temperature when body temperatures change rapidly.
Article
MORA-RODRIGUEZ, R. Influence of aerobic fitness on thermoregulation during exercise in the heat. Exerc. Sport Sci. Rev., Vol. 40, No. 2, pp. 79-87, 2012. It is believed that the adaptations induced by aerobic training would prevent athletes from overheating while retaining body electrolytes during exercise in the heat. Data from our laboratory suggest that aerobic training is not enough to induce these adaptations. This review considers the factors that can lead to hyperthermia in trained and untrained populations when exercising in the heat.
Rectal (Tre), oral (Tor) and oesophageal (Tes) temperatures were measured in five exercising subjects exposed for two hours to five conditions (1) a steady condition (WR) involving a constant work load (50 W) at a constant air temperature (Ta = 36.5 degrees C); (2) air temperature variations (delta Ta) between 28 degrees C and 45 degrees C and (3) between 23 degrees C and 50 degrees C at constant work load (50 W); (4) and (5) to work load variations (delta W) between 25 W and 75 W at a constant Ta (= 36.5 degrees C). Oral temperature recordings were taken sublingually and were either continuous or discontinuous. When discontinuous, the time needed for Tor to stabilize after the mouth opening was taken into account. The respective reliability of Tor and Tre as estimates of Tes were compared in each condition. Results showed that the resting (Tor - Tes) difference (+ 0.12 degrees C) was barely modified after two hours of exposure, whereas Tre overestimated Tes by 0.2 degrees C to 0.4 degrees C depending on the condition. The Tor variations were highly correlated with Tes variations under steady condition and under air temperature variations. In these conditions, Tor represented the best estimate of Tes. Under work-load variations, Tor was less closely related to Tes than was Tre. It is suggested that the relative inertia of Tor to step changes in exercise intensity could be ascribed to work induced variations in mouth blood flow.
Article
This study sought to determine whether levels of fitness, habitual physical activity, and fatness are associated health-related quality of life and mood in older persons. The subjects were men (n = 38) and women (n = 44), ages 55 to 75 years, who had milder forms of hypertension, but who were otherwise healthy and not engaged in a regular exercise or diet program. Aerobic fitness was assessed by maximal oxygen uptake during treadmill testing, muscle strength by a one-repetition maximum, habitual activity by questionnaire, fatness by dual-energy x-ray absorptiometry, and body mass index. Health-related quality of life was assessed by the Medical Outcomes Study SF-36, and mood by the Profile of Mood States (POMS). Correlations were determined by bivariate and multivariate regression. Higher aerobic fitness was associated with more desirable outcomes, as indicated by the POMS anger and total mood disturbance scores and by the SF-36 bodily pain, physical functioning, vitality, and physical component scores. Increased fatness was associated with less desirable outcomes, as indicated by the POMS anger, depression, and total mood disturbance scores and by the SF-36 bodily pain, physical functioning, role-emotional, role-physical, social functioning, vitality, and physical component scores. Higher physical activity was associated with an increased POMS score for vigor and a decreased SF-36 score for bodily pain. Strength was not related to health-related quality of life or mood. Aerobic fitness was the strongest predictor of the SF-36 score for vitality and the POMS score for total mood disturbance, whereas fatness was the strongest predictor of the POMS anger score and the SF-36 bodily pain, physical functioning, and physical component scores. Even in the absence of regular exercise and a weight-loss diet, relatively small amounts of routine physical activity within a normal lifestyle, slight increases in fitness, and less body fatness are associated with a better health-related quality of life and mood.
Article
The SensorTouch thermometer performs an infrared measurement of the skin temperature above the Superficial Temporal Artery (STA). This study evaluates the validity and the accuracy of the SensorTouch thermometer. Two experiments were performed in which the body temperature was measured with a rectal sensor, with an oesophageal sensor and with the SensorTouch. After entering a warm chamber the SensorTouch underestimated the core temperature during the first 10 minutes. After that, the SensorTouch was not significantly different from the core temperature, with an average difference of 0.5 degrees C (SD 0.5 degrees C) in the first study and 0.3 degrees C (SD 0.2 degrees C) in the second study. The largest differences between the SensorTouch and the core temperature existed 15 minutes after the start of the exercise. During this period the SensorTouch was significantly higher than the core temperature. The SensorTouch did not provide reliable values of the body temperature during periods of increasing body temperature, but the SensorTouch might work under stable conditions.
Article
Limits of agreement provide a straightforward and intuitive approach to agreement between different methods for measuring the same quantity. When pairs of observations using the two methods are independent, i.e., on different subjects, the calculations are very simple and straightforward. Some authors collect repeated data, either as repeated pairs of measurements on the same subject, whose true value of the measured quantity may be changing, or more than one measurement by one or both methods of an unchanging underlying quantity. In this paper we describe methods for analysing such clustered observations, both when the underlying quantity is assumed to be changing and when it is not.
Article
The purpose of this study was to compare tympanic (measured by infrared thermometry; Tty- (IRED)) with rectal and esophageal temperatures (T(REC) and T(ES)) during exercise in the heat. During Experiment 1, nine subjects pedaled for 55 min in a hot-dry environment (37 degrees C; 27% humidity) in still-air (<0.2 m/s) and for 10 additional min using water ingestion, wind and ice to cool them down. During Experiment 2, subjects pedaled for 90 min in a similar environment but with airflow at 2.5 m/s. Pearson correlation coefficients (r) and Bland-Altman plots were calculated. In Experiment 1, Tty-(IRED) and T (REC) were highly correlated (r=0.83; p<0.001) with close agreement (-0.08+/-0.4 degrees C). Overall Tty-(IRED) was significantly correlated with T(ES) (r=0.91; p<0.001). Cold water ingestion did not affect Tty-(IRED) or T(REC) but lowered T(ES). Wind and ice application lowered Tty- (IRED) below T(REC) (p<0.05). During Experiment 2, Tty-(IRED) was lower than T(REC) (p<0.05) and the difference increased throughout exercise as hyperthermia developed resulting in low agreement (-1.01+/-1.1 degrees C). In conclusion, Tty- (IRED) dangerously underestimates T(REC) when exercising in a hot environment with airflow or during a cooling treatment. However, it could correctly detect hyperthermia during exercise in a hot still-air environment.
  • DJ Casa
Physical exercise in hot climates: physiology, performance, and biomedical issues. In: Medical aspects of harsh environments. Textbooks of military medicine
  • M N Sawka
  • K B Pandolf
  • MN Sawka
Sawka, M. N., and K. B. Pandolf. Physical exercise in hot climates: physiology, performance, and biomedical issues. In: Medical aspects of harsh environments. Textbooks of military medicine, edited by K. Pandolf, and R. Burr. Washington, D.C.: Office of the Surgeon General, United States Army, 2001, pp. 87-133.
Irwin and Rippe’s intensive care medicine
  • R S Irwin
  • C M Lilly
  • P H Mayo
  • J M Rippe
  • RS Irwin
Irwin, R. S., C. M. Lilly, P. H. Mayo, and J. M. Rippe. Irwin and Rippe's intensive care medicine. New York: Wolters Kluwer, 2018.