Article

A laboratory validation study of comfort and limit temperatures of four sleeping bags defined according to EN 13537 (2002)

Authors:
  • TTRI (Taiwan Textile Research Institute)
  • Nederlands Instituut Publieke Veiligheid (NIPV)
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Abstract

In this study, we validated comfort and limit temperatures of four sleeping bags with different levels of insulation defined according to EN 13537. Six male subjects and four female subjects underwent totally 20 two-hour exposures in four sleeping bags at four intended testing temperatures: 11.2, 3.8, 2.1 and -9.0 °C. The subjective perceptions and physiological responses of these subjects were reported and analyzed. It was found that the EN 13537 defined comfort temperature and limit temperature were underestimated for sleeping bags MA3, HAG and MAM. The predictions are so conservative that further revision may be required to meet the requirements of both manufacturers and consumers. In contrast, for the sleeping bag MA0 with a low level of insulation, the limit temperature defined by EN 13537 was slightly overestimated. In addition, two individual case studies (-28.0 and -32.0 °C) demonstrated that low toe temperatures were widely observed among the male and female subjects, although the mean skin temperatures were almost within the thermoneutrality range (32.0-34.0 °C). It seems that the IREQ model (ISO 11079) overestimated both the comfort and limit temperatures of the sleeping bags. Finally, traditional sleeping bags may be required to be re-designed to provide consumers both whole body comfort as well as local thermal comfort at feet/toes or users need to be made aware of the higher need for their insulation.

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... temperature thresholds at which male and female users could have an 8-hour sleep without feeling cold). [3][4][5][6][7][8][9] The aforementioned four temperatures are normally determined by thermal manikin test. [3][4][5][6][7][8][9] However, not all manufacturers strictly follow the EN13537 (2012) standard to label these operation temperatures. ...
... [3][4][5][6][7][8][9] The aforementioned four temperatures are normally determined by thermal manikin test. [3][4][5][6][7][8][9] However, not all manufacturers strictly follow the EN13537 (2012) standard to label these operation temperatures. Hence, temperatures labeled by different manufacturers may vary largely even for sleeping bags with similar thermal insulation. ...
... On the other hand, the existing temperature prediction model adopted by the EN 13537 (2012) standard has been criticized by users for giving less consideration to local thermal comfort. [6][7][8][9] To improve local thermal comfort in the feet region, we developed an electrically heated sleeping bag in our previous studies 6-8 by incorporating two heating pads into traditional sleeping bags in the feet region, and a series of research studies have been performed to assess the performance of the electrically heated sleeping bag. [6][7][8] It was found that the electrically heated sleeping bag could greatly improve the wearers' local thermal comfort, as well as the foot and toe temperatures. ...
Article
In this study, a novel smart electrical heating sleeping bag was developed by incorporating a proportional-integral-derivative (PID) heating control system into a traditional sleeping bag. The smart sleeping bag was aimed to maintain human feet temperature within the thermoneutral range (i.e., 25.0-34.0 °C) by automatically adjusting the heat power to the feet region based on real-time human toe temperatures. Subsequently, the performance of the newly developed smart sleeping bag in improving human thermal comfort was investigated by human trials. Eight female subjects underwent two 8-hour sleep trials i.e., the smart sleeping bag with power turned on (SleepingbagHT) and the smart sleeping bag with power turned off (SleepingbagCON). All trials were performed at an air temperature of 6.1±0.5 °C (i.e., the EN 13537 defined comfort temperature for females), the RH= 80±5% and the air velocity was 0.4±0.1 m/s. It was found that SleepingbagHT could maintain both the foot and toe temperatures within the thermal neutral range as well as keep the local-, and whole-body thermal and comfort sensations in thermal neutral state throughout the 8-hour cold exposure. In contrast, linearly decreasing foot and toe temperatures and aggravated local-, and whole-body thermal and comfort sensations were detected in SleepingbagCON within a 4.5-hour cold exposure. It could thus be concluded that the smart electrical heating sleeping bag was able to provide wearers an 8-hour comfortable sleep in the studied cold environment.
... The limit temperature refers to the lower threshold temperature for a standard man sleeping in a cured up body posture for eight hours without feeling cold under the standard condition. Previous studies have shown that the comfort temperature and limit temperature were sometimes questioned by users and scientists 3 . This is because some manufacturers defined these two temperatures based on qualitative methods, such as customers' feedback and assessments from bag's thickness, weight and loftiness 4 . ...
... It seems that both the comfort temperature and the limit temperature defined by the models failed to take care of local thermal comfort in the feet 8 . Lin et al. 3 investigated the physiological and psychological responses of females and males in different sleeping bags under both the EN 13537 (2012) and the IREQ model defined temperatures. Although the mean skin temperature was within its thermal neutral range, almost all subjects had continuously dropping toe temperatures throughout the two-hour exposure. ...
... Thus, our results have reconfirmed that the local region of the human body was inadequately protected while using the studied sleeping bag under the environmental temperatures defined by EN 13537 (2012). Lin et al. 3 detected that T toe of females in a traditional sleeping bag decreased to 21.1 °C at the 120 th min while exposed to EN 13537 defined comfort temperature (i.e., 3.8 °C). In this study, T toe of females decreased to 21.3 °C at the 120 th min. ...
Article
Full-text available
Previous studies have revealed that wearers had low skin temperatures and cold and pain sensations in the feet, when using sleeping bags under defined comfort and limit temperatures. To improve wearers' local thermal comfort in the feet, a novel heating sleeping bag (i.e., MARHT) was developed by embedding two heating pads into the traditional sleeping bag (i.e., MARCON) in this region. Seven female and seven male volunteers underwent two tests on different days. Each test lasted for three hours and was performed in a climate chamber with a setting temperature deduced from EN 13537 (2012) (for females: comfort temperature of -0.4 {degree sign}C, and for males: the limit temperature of -6.4 {degree sign}C). MARHT was found to be effective in maintaining the toe and feet temperatures within the thermoneutral range for both sex groups compared to the linearly decreased temperatures in MARCON during the 3-hour exposure. In addition, wearing MARHT elevated the toe blood flow significantly for most females and all males. Thermal and comfort sensations showed a large improvement in feet and a small to moderate improvement in the whole body for both sex groups in MARHT. It was concluded that MARHT is effective in improving local thermal comfort in the feet.
... A good bedding surface is universally accepted as one that provides comfortable support to the subject. The physical variables associated with comfort include spinal alignment (Lahm and Iaizzo, 2002;Ray, 1991), contact pressure or weight distribution, interface skin temperature, and vapor exchange between the subject and the bedding system (Rithalia and Kenney, 2000) achieve the local need of body sites [4]. Consumer mattress report of America expects temperature control mattress is one of the mattress trends in 2014. ...
... For the cold extremities, complaining frequently occurred of difficulties initiating sleep (DIS) from thermal discomfort [8]. An assessment of thermal comfort of four sleeping bags found that although the overall temperature is rising, but the temperature of the toes are showing stable or slightly decreased, besides, the research suggests that there needs a design for local foot thermal comfort of sleeping bag [4]. Overall, local thermal comfort is as important as whole body thermal comfort. ...
... Activity data were automatically scored after pressing the event marker [1]. A general method to investigate participants' whole body comfort and local thermal comfort is to affix thermistors on certain body sites interested to comprehend [4,5,22]. By means of sleep monitoring data analysis, specific sleep positions of body segments corresponding to mattress were obtained. ...
Article
Full-text available
Sleep thermal comfort is one of the critical factors affecting sleep quality. In recent years, research not only investigates ways and products to improve whole body thermal comfort, but attaches great importance to local thermal comfort of peripheral skin. Healthy sleep containing cycle position change is considered to regulate body temperature. Mattress design contacted to human body provides direct impact on sleep comfort. Twelve healthy participants had general level in BMI were recruited in 2-day sleep monitoring in simulated laboratory condition to evaluate two different design mattresses, one due to body segment location on the mattress, the other is according to position change during sleep. Sleep position, sleep quality data and skin temperature were examined. Through statistical analysis, this study deduced the relation between mattress design and all dependent variables of appraisement. All night sleep position change cycle and skin temperature in supine was slightly more stable was more regular and had less short phase body movement of the design due to sleep position change. Furthermore, the design due to position change contributed to reduction of sleep disturbance. Also, it promoted distal skin warming. The consequence indicated mattress design on the basis of posture change conformed particularly demands of local thermal comfort and enhanced sleep quality.
... The limit temperature is the temperature at which a standard man could sleep for 8 hours without feeling cold with a curled up posture [3]. Previous documents [1,4,5] have demonstrated that manufacturers used difference methods to determine the comfort and limit temperatures of the sleeping bags. It has been reported that labelled temperatures defined by different methods varied greatly for bags with similar levels of insulation [4]. ...
... For instance, some manufacturers label the temperatures based on customers' feedback; some manufacturers determine the temperatures based on the sleeping bag's physical properties such as the thickness, weight and loft. Other manufacturers rate the temperatures by comparing the design and material of their sleeping bags with those of their competitors [4,5]. ...
... Local thermal discomfort at the extremities such as the human feet has been widely reported even though the mean skin temperature of the wearers fell within the thermoneutral range (i.e. 32-34 °C) [5,8]. Lin et al. [5] found that the toe temperature of the subjects dropped continuously and rapidly in sleeping bags under the EN 13537 (2002) defined operating temperatures. ...
Article
Full-text available
In this study, two novel electrically heated sleeping bags were developed by inserting heating pads into two traditional sleeping bags at the foot region. The physiological and psychological responses of six human subjects (3 males and 3 females) while wearing the non-heated sleeping bags (i.e., when heating power was turned off) and the electrically heated sleeping bags (i.e., when heating power was turned on) were examined. It was found that the electrically heated sleeping bags could dramatically improve and maintain the microenvironment condition at the feet area within the thermal neutral range (i.e., 24-34 °C). Besides, the heated sleeping bags significantly improved the subjective perceptions at the feet. In contrast, the toe temperature of the subjects in the non-heated sleeping bags dropped linearly to 15 °C and cold discomfort and pain sensations were reported at the end of the 3-hour cold exposures. It was thus concluded that the new electrically heated sleeping bags could effectively improve the human thermal comfort at the feet.
... In past research, environmental factors such as temperature, humidity, and CO 2 concentration in shelters were measured [5,6] as well as thermal comfort [7,8] , and thermal performance analysis of an emergency shelter [9] . Moreover, comfort and limit temperatures of four sleeping bags defined according to the standard were validated [10] . However, there is no research investigating the influence on the human body when a person is sleeping during night in a shelter of winter although daytime nap was studied in a sleeping bag at 15 °C in the climatic chamber [11] . ...
... Both body heat storage rates of Blankets and Futon were negative, and the body heat storage of Blankets ( −6.2 W) was less than that of Futon ( −5.3 W). In the previous study the experiment lasted for 2 h using four sleeping bags of 3.71, 5.33, 5.95 and 8.60 clo at four intended testing temperature: 11.2, 3.6, 2.1 and −9.0 °C [10] . The body heat storage rates were between −0.24 and 2.84 W. ...
Article
The aim of this study is to investigate the effects of a cold environment on sleep, thermoregulatory responses, and subjective sensations during sleep in winter using disaster relief blankets (Blankets) and ordinary futons (Futon). The clo insulations of Blankets and Futon were 1.3 clo and 3.1clo respectively, measured using a thermal manikin in advance. The average air temperature in the gymnasium before going to bed was 5.9°C, while at dawn it was 3.6°C. The sleep efficiency index, which was measured by actigraphy, decreased significantly in the first night when using Blankets (85%) compared to Futon (94%). The average microclimate temperature between the human body and the bedding was 21.4°C for Blankets and 23.5°C for Futon. The mean skin temperature was significantly lower for sleeping times using Blankets (32°C) than when using Futon (32.8°C). However, no significant differences in rectal temperature and heart rate were found between the Blankets and Futon. After sleep, the participants felt significantly colder for whole body and upper body when using Blankets than Futon. Sleeping in a low temperature environment using insufficient bedding such as a disaster blanket significantly lowers the mean skin temperature by decreasing skin temperature at the distal end and back. Especially, regarding the first night of an emergency evacuation, it became clear that even in healthy young men, sleep was disturbed in low temperature environments.
... In past research, environmental factors such as temperature, humidity, and CO 2 concentration in shelters were measured [5,6] as well as thermal comfort [7,8] , and thermal performance analysis of an emergency shelter [9] . Moreover, comfort and limit temperatures of four sleeping bags defined according to the standard were validated [10] . However, there is no research investigating the influence on the human body when a person is sleeping during night in a shelter of winter although daytime nap was studied in a sleeping bag at 15 °C in the climatic chamber [11] . ...
... Both body heat storage rates of Blankets and Futon were negative, and the body heat storage of Blankets ( −6.2 W) was less than that of Futon ( −5.3 W). In the previous study the experiment lasted for 2 h using four sleeping bags of 3.71, 5.33, 5.95 and 8.60 clo at four intended testing temperature: 11.2, 3.6, 2.1 and −9.0 °C [10] . The body heat storage rates were between −0.24 and 2.84 W. ...
Article
This study was aimed to investigate sleep in evacuation shelter-analogue settings in winter using blankets for disaster relief and ordinary futon. Subject experiment was conducted to examine the sleep variables using actigraphy and environmental conditions in winter gymnasium. The subjects completed questionnaires regarding their thermal sensation, comfort sensation, fatigue, and subjective sleepiness before and after the sleep. The subjects felt more coldness on their head and peripheral parts of the body using the emergency blankets than the futon during the sleep. Moreover, fatigue was felt more on the lower back and lower extremities from using emergency blankets than the futon after sleep.
... In past research, environmental factors such as temperature, humidity, and CO 2 concentration in shelters were measured [5,6] as well as thermal comfort [7,8] , and thermal performance analysis of an emergency shelter [9] . Moreover, comfort and limit temperatures of four sleeping bags defined according to the standard were validated [10] . However, there is no research investigating the influence on the human body when a person is sleeping during night in a shelter of winter although daytime nap was studied in a sleeping bag at 15 °C in the climatic chamber [11] . ...
... Both body heat storage rates of Blankets and Futon were negative, and the body heat storage of Blankets ( −6.2 W) was less than that of Futon ( −5.3 W). In the previous study the experiment lasted for 2 h using four sleeping bags of 3.71, 5.33, 5.95 and 8.60 clo at four intended testing temperature: 11.2, 3.6, 2.1 and −9.0 °C [10] . The body heat storage rates were between −0.24 and 2.84 W. ...
Article
The aim of this study was to investigate sleep in evacuation shelter-analogue settings in winter using disaster relief blankets and ordinary futons. Subject experiments were conducted to examine the sleep variables using actigraphy and the environmental conditions in a gymnasium during winter. The Sleep Efficiency Index and sleeping time decreased significantly in Hie first night when using disaster blankets. The mean skin temperature was significantly lower for sleeping times using disaster blankets. However, no significant difference in rectal temperature was found between the blankets and a pair of futons.
... Local thermal discomfort at the body extremities such as the feet has been widely reported, albeit that the mean skin temperature of the wearers is still within the thermoneutral range (i.e. 32-34 ∘ C) when using sleeping bags at their predefined comfort temperatures [110,112,113,119]. Huang [114] observed a similar tendency of decrease in toe temperatures on both male and female subjects when comparing the five models (i.e. the EN 13537 [107] model, the Goldman's model, the KSU model, the Belding's model, and the den Hartog's model). ...
... Huang [114] observed a similar tendency of decrease in toe temperatures on both male and female subjects when comparing the five models (i.e. the EN 13537 [107] model, the Goldman's model, the KSU model, the Belding's model, and the den Hartog's model). Lin et al. [112] reported that the foot temperature underwent a continuously and rapidly drop in sleeping bags under the EN 13537 [107] defined operating temperatures. Within the two hours exposure, the foot temperature dropped to almost 14 ∘ C, at which strong cold sensations occurred even the mean skin temperature was well maintained within the thermal neutral range (i.e. ...
Chapter
Full-text available
Thermal comfort property is one of the most important properties to fibrous materials, and it will affect the human thermophysiological responses. The thermal comfort property of fibrous materials depends heavily on their heat and moisture transfer capability. To characterize the heat and moisture transfer property, different techniques and instruments have been developed. Also, different techniques have been incorporated into clothing systems to improve the clothing comfort property by cooling or heating the microclimate between the human body and clothing systems. This chapter reviews the human thermoregulatory system and the heat and moisture transfer properties of fabrics and full‐scale clothing. Innovative personal cooling strategies used to improve clothing wear comfort are also described. Finally, the future trends on the development of new fibrous materials and performance measurement techniques are addressed.
... The foot area of the sleeping bag was significantly colder in the Wood than in the CC after sleep, despite there being no significant differences for the back area. Previous studies indicated that toe temperature corresponds with thermal comfort when using sleeping bags (Lin et al., 2013;Livingstone et al., 1988). In men sleeping in a Ta between 0 and 5 C and using sleeping bags, foot Tsk dropped considerably towards morning, which was a major reason for disturbed sleep (Scholander et al., 1958). ...
... The manufacturers employ different methods to label the minimum temperature use of sleeping bags, and these often lack validity (McCullough and Rohles, 1983). Further modifications are required for EN13537 (Lin et al., 2013). Discomfort not attributable to thermal factors were reported by 11 out of 14 subjects (e.g., lower back pain), and these should also be taken into account. ...
Article
Fourteen healthy male subjects slept from 13:30 to 15:30 under ambient temperature and relative humidity maintained at 15 °C and 60%, respectively. They slept under two conditions: in a sleeping bag on wooden flooring (Wood) and in a sleeping bag with corrugated cardboard between the bag and the flooring (CC). Polysomnography, skin temperature (Tsk), microclimate, bed climate, and subjective sensations were obtained. The number of awakenings in the CC had significantly decreased compared to that in the Wood. The mean, back, and thigh Tsk, and bed climate temperature were significantly higher in the CC than that in the Wood. Subjective thermal sensations were warmer in the CC than in the Wood. These results suggest that using corrugated cardboard under a sleeping bag may reduce cold stress, thereby decreasing the number of awakenings and increasing subjective warmth; the mean, back, and thigh Tsk; and bed climate temperature.
... Now, most of the studies and bedding system designs are focused on the measurement of back pressure to improve sleep quality and presented mainly in the way of mattress firmness, but lack of exploring the relationship between the sleeping postures and mattress design. As mattress is the familiar one, to achieve the local need of body sites [3] and sleep thermal comfort is one of the critical factors that affects sleep quality; the design of a bedding system surface that contacts the human body provides direct impact on sleep comfort. Several studies have investigated the thermal sensation and comfort of local and whole body. ...
... We speculated that thermal comfort of extremities had a slight increase and thus improved whole body thermal comfort probably because of the design on the first layer. As mentioned in the research of Li-Yen [3], whole body thermal comfort could be improved by the local thermal comfort, whereas this study also had the same result. Although the perceptions of thermal comfort of other body parts of mattress A increased, thermal comfort of the forehead remain similar to testing with the mattress B. One possible reason for the result may be the design of the second layer, which increased the heat dissipation of the torso. ...
Article
Full-text available
Recently, mattresses are designed and divided horizontally into several zones according to the main body segments under the static condition. However, different body segments have different thermal characteristics and sleeping postures change unconsciously during the night. Thus, the movements of the extremities should be taken into consideration in a bedding system design. With this in mind, the purposes of this study are: (1) to observe the changes of sleeping posture; and, (2) to develop an innovative mattress design based on the distributions of the body positions. A purposive sample of ten healthy participants (five males and five females) were selected to conduct the sleep monitoring in order to observe the dynamic and continuous features of their all-night sleeping postures. The images captured were then overlaid in order to acquire the distributions of the body positions on a mattress. The outcomes of sleep posture characteristics were used to provide a reference to conduct the mattress design to satisfy the needs of different body segments. Morphological analysis was used to find out the most suitable attributes for a mattress design. Finally, an innovative mattress design has been developed in this study. The proposed mattress has a four-layer sandwiched structure. A pilot study was conducted to evaluate the effect of the mattress on thermal comfort with 10 participants and a questionnaire was used to evaluate their subjective feelings on thermal comfort.
... The EN 13537 (2012) and ASTM F1720 (2014) standards are widely used to determine the thermal insulation of sleeping bags by means of thermal manikin. Previous studies have found that local thermal discomfort at feet was often seen despite the mean skin temperature was well within thermoneutral range under the defined comfort and limit temperature [1]. Thus, it is meaningful to design smart heating sleeping bags to improve the local thermal comfort of the users. ...
... It has proven that the smart heating sleeping bag could keep the users foot and toe remaining comfort throughout the testing period under * Correspondence: dr.famingwang@gmail.com 1 Laboratory for Clothing Physiology and Ergonomics (LCPE), the National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, 215123 China Full list of author information is available at the end of the article defined temperature. Besides, the newly developed smart sleeping bags could significantly improve local thermal comfort under the defined wear temperature. ...
Article
Full-text available
Sleeping bags are portable products, which are essential for sleeping outdoors. Generally, a sleeping bag is comprised of an outer layer, an inner lining layer and the filler. The EN 13537 (2012) and ASTM F1720 (2014) standards are widely used to determine the thermal insulation of sleeping bags by means of thermal manikin. Previous studies have found that local thermal discomfort at feet was often seen despite the mean skin temperature was well within thermoneutral range under the defined comfort and limit temperature [1]. Thus, it is meaningful to design smart heating sleeping bags to improve the local thermal comfort of the users. In this study, a novel smart sleeping bag was developed by incorporating heating fabrics into the feet region of the bag. The physiological and psychological responses when using traditional sleeping bag and the smart sleeping bag were investigated and compared.
... More studies are required to explore the interaction between thermal comfort perception and heat exchange in cold environments (Holm er, 2004). A laboratory validation of EN 13537 on sleeping bags has been recently reported (Lin et al., 2013 ). In contrast with the temperature ratings for sleeping bags, physical activities while wearing cold weather protective clothing play a more important role in determining the temperature ratings for thermal comfort. ...
... The toe temperature dropped during the first 15 min in the condition of À30.6 C, and then in both environmental conditions it increased continuously because the subjects were walking on the treadmill so that the lower extremities had better heat production and blood circulation. Our earlier studies showed similar low toe temperature and high insulation requirement for the toes for sleeping bags (Lin et al., 2013). These results on the extremities are largely consistent with perceived thermal sensations and thermal comfort except that the little toe temperature was rather low in the condition at À30.6 C. It should be noted that the little toe and little finger are the most sensitive regions of the feet and hands, probably due to a larger surface area to mass ratio and faster heat loss. ...
Article
American standard ASTM F2732 estimates the lowest environmental temperature for thermal comfort for cold weather protective clothing. International standard ISO 11079 serves the same purpose but expresses cold stress in terms of required clothing insulation for a given cold climate. The objective of this study was to validate and compare the temperature ratings using human subject tests at two levels of metabolic rates (2 and 4 MET corresponding to 116.4 and 232.8 W/m2). Nine young and healthy male subjects participated in the cold exposure at 3.4 and −30.6 °C. The results showed that both standards predict similar temperature ratings for an intrinsic clothing insulation of 1.89 clo and for 2 MET activity. The predicted temperature rating for 2 MET activity is consistent with test subjects' thermophysiological responses, perceived thermal sensation and thermal comfort. For 4 MET activity, however, the whole body responses were on the cold side, particularly the responses of the extremities. ASTM F2732 is also limited due to its omission and simplification of three climatic variables (air velocity, radiant temperature and relative humidity) and exposure time in the cold which are of practical importance. Applied Ergonomics 46 (2015) 44-53 (http://authors.elsevier.com/a/1Pn~rrfpAEdy)
... In order to determine the thermal insulation of sleeping bag systems, EN 13537 and ASTM F1720 standards were published. The possible parameters that may cause an error in determining insulation values of sleeping bags according to EN 13537 standards were discussed by Lin et al. (2013). It was concluded that the impact of air velocity, mattress insulation, and conditioning time was significant on determining the total thermal insulation of sleeping bags. ...
Article
Sleeping bags are a common type of personal protective equipment that maintains the individual’s comfort during rest in an open environment. One of the main purposes of utilizing sleeping bags is protection against cold weather in order to prevent body heat loss. However, during use, the exertion of body pressure on the sleeping bag may impact its protective performance. In this study, the influence of body pressure on the thermal insulation of two sleeping bags containing solid and hollow polyester fibers was investigated with consideration of body pressure in the head, shoulder, hips, and feet regions. Moreover, the sleeping bag layer’s thickness and compressibility variations were analyzed. The results revealed that both sleeping bag layers suffer from the thickness and thermal insulation reduction under body pressure, especially in the hip area. However, due to the entrapped air inside the fiber structure, hollow fibers presented enhanced thermal resistance.
... Havenith et al. (2010) estimated R e and ventilation of clothing on human under two different types of trace gas. Lin et al. (2013) evaluated comforts of four sleeping bags at −28 and −321C, respectively. ...
Article
Full-text available
Purpose The purpose of this paper is to compare the evaporative resistance and thermal insulation of clothing measured by thermal manikin “Walter” using uniform and non-uniform skin. Design/methodology/approach The non-uniform skin with different perspiration rates was made by laminating a silicone layer on the inner side of a uniform skin. The thermal manikin was then covered with prepared non-uniform skin as well as uniform one. Four types of clothing ensembles were tested. Findings The relative intensity of perspiration rate was realized in different part of “Walter” skin, which was close to the perspiration rate of human being. There was a strong correlation between uniform skin and non-uniform skin. The thermal insulation and evaporative resistance of clothing measured on the non-uniform skin were higher than the ones determined on the uniform skin. However, their moisture permeability index showed the reversed tendency. Research limitations/implications The implication of the research is to investigate the differences between uniform skin and non-uniform skin for manikin “Walter.” This is possibly useful in correcting and predicting more accurate thermal insulation and evaporative resistance of clothing measured by “Walter” with a uniform skin in future. Originality/value It was more accurate using non-uniform skin in evaluating thermal and wet comfort comparing to uniform skin.
... similar temperature predictions. However, the temperature rating by ASTM F2732 for 2 METS activity with 1.89 clo clothing was 3.0 °C higher than that predicted by the ISO 11079. Predicted temperature rating is in line with the observed thermophysiological responses. For the 4 METS activity, predictions are on the cold side (i.e., the risky side). Lin et al . ( 2013b ) made a tentative experimental study with human subjects. They explored the possibility of using the IREQ model to predict temperature ratings for sleeping bags. It was found that the IREQ model overestimated both the comfort and limit temperatures of the two sleeping bags studied (i.e., predictions are on the cold side). Alfano et al . ...
Chapter
In cold, wet and/or windy conditions, cold stress can be a great threat to human body. If protection is insufficient, local cold injuries and hypothermia may occur. In order not to put the human body at risk of cold stress, adjustments such as increase the activity level, early termination of the work or move to a warmer shelter should be made. In this chapter, the definition of “cold” and effects of cold on human function, performance and health are described. Cold associated injuries including non-freezing cold injuries (NFCI) and freezing cold injuries (FCI) are also outlined. Additionally, assessment methods of cold stress and modelling of cold strain are discussed. The chapter concludes with work practices for prevention of cold injuries for various cold workplaces.
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Personal conditioning system (PCS) is receiving considerable attention due to its energy-saving potential and the ability to satisfy individual comfort requirements. As a part of PCS, personal heating systems can maintain human thermal comfort in cold environments, which leads to their potential role of important heating mode in cold winter, especially in the Hot Summer and Cold Winter regions of China. In order to better promote the development and application of personal heating systems, this paper reviews the published studies. Personal heating systems can be divided into four types based on the mode of heat transfer: conductive, convective, radiative and combinative type. Characteristics of each category and respective devices are introduced. Furthermore, identifying the effects of personal heating on thermal comfort and the models for predicting or evaluating thermal comfort during local heating. This paper would provide users with a guideline for choosing suitable heating equipment during winter.
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Background: This study aims to evaluate the effectiveness of newly designed evaporative cooling short pants (ECSP) in decreasing physiological and perceptual heat strain under hot/dry laboratory conditions. Methods: At the first, an evaporative cooling short pants was designed. Then, to evaluate this cooling garment, 12 healthy men participated in the test. The subjects performed the test at two stages, including test with regular pants and test with ECSP. During each stage, the physiological and perceptual parameters, including heart rate, local temperature in thighs, ear temperature, sweat rate, thermal sensation, sweat sensation, and thermal comfort, were measured every 5 minutes for 60 minutes. Results: The results showed that use of the cooling short pants compared to regular pants could not significantly decrease the parameters of heart rate (P=0.547), ear temperature (P=0.487), sweat rate (P=0.368), local and general sweat sensation (P=0.632) and (P=0.368) respectively. However, use of this garment significantly decreased the mean value of local temperature in thighs by 3 °C (P=0.002), local and general thermal sensation of body by 1.4 (P=0.002) and 0.4 (P=0.006), respectively and increased the mean values of local and general thermal comfort by 1.2 (P=0.003) and 0.7 (P=0.002), respectively. Conclusion: The results revealed that designed evaporative cooling short pants reduced local temperature in thighs and had positive effect on controlling the perceptual heat strain.
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Purpose To understand the thermal insulation of four common structures of sleeping bags and factors influencing the thermal insulation as well as the thermal comfort of people who use four kinds of sleeping bag structures. Design/methodology/approach Four samples corresponding to four common sleeping bag structures were made and their thermal properties were investigated through a combination of objective instrument measurement and subjective human subject tests. Findings The porosity of the samples and the length of the interlining had a main impact on the thermal resistances of the four sleeping bag structures. The thermal sensation ratings and the thermal resistances had good consistency. There was a strong correlation between human physiological parameters and thermal sensation evaluation. The male and female have significant differences in thermal sensation of different structures of sleeping bags. Originality/value Instrument measurement and human subject tests were combined to study the thermal properties of sleeping bag structures, which had little attention in the past in research fields.
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Thesis (Ph. D.)--Kansas State University, 2003. Includes bibliographical references (leaves 45-46).
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Twenty-two male Caucasians, aged 20-47 yr, were exposed in a cold room to air temperatures of -33 degrees C while lying in sleeping bags for 2 h. Skin and rectal temperatures as well as electromyographic activity of the chin, forearm, and thigh, were recorded. Shivering occurred in all the subjects, even though skin temperatures were maintained between 31 and 33 degrees C. It is suggested that a counter-current heat exchange occurs whereby the warm blood of the common carotid artery is cooled by cool venous blood in the jugular veins. This cooled arterial blood, in irrigating the hypothalamus, causes shivering.
Standard Test Method for Measuring Thermal Insulation of Clothing Using a Heated Manikin Standard Test Method for Measuring Thermal Insulation of Sleeping Bags Using a Heated Manikin Cold-induced shiv-ering in men with thermoneutral skin temperature
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References ASTM F1291, 2010. Standard Test Method for Measuring Thermal Insulation of Clothing Using a Heated Manikin. American Society for Materials and Testing, PA. ASTM F1720, 2011. Standard Test Method for Measuring Thermal Insulation of Sleeping Bags Using a Heated Manikin. American Society for Materials and Testing, PA. Buguet, A.G.C., Livingstone, S.D., Reed, L.D., Limmer, R.E., 1976. Cold-induced shiv-ering in men with thermoneutral skin temperature. Journal of Applied Physi-ology 41 (2), 142e145. Burton, A.C., Edholm, O.G., 1955. Man in a Cold Environment. Arnold, London.
Sleep Well Part I Temperature Ratings: A Review of Temperature Standards for Sleeping Bags
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Farnworth, M., Ackermann, B., Holand, B., Parsons, M., Rose, M., 2003. Sleep Well Part I Temperature Ratings: A Review of Temperature Standards for Sleeping Bags. Available from: http://www.mammut.ch/images/Mammut_Sleep_well_ pt1_E.pdf (accessed 05.01.12.).
Evaluation of EN 13537 and other models for predicting temperature ratings of sleeping bags The effect of auxiliary products on the insulation provided by sleeping bag systems
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McCullough, E.A., Huang, J., Jones, B.W., 2005. Evaluation of EN 13537 and other models for predicting temperature ratings of sleeping bags. In: Holmér, I, Kuklane, K, Gao, C. (Eds.), Proceedings of the 11th International Conference on Environmental Ergonomics (ICEE), May 22e26, 2005, Ystad, Sweden, pp. 425e428. McCullough, E.A., Zuo, J., Huang, J., 2009. The effect of auxiliary products on the insulation provided by sleeping bag systems. In: 2009 ITAA (International Textile and Apparel Association) Proceedings, October 28e31, 2009, Wash-ington, USA, #66.
mean skin temperature of the female subject; Ttoe_f, toe temperature of the female subject
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Tsk_f, mean skin temperature of the female subject; Ttoe_f, toe temperature of the female subject. L.-Y. Lin et al. / Applied Ergonomics 44 (2013) 321e326
Mechanisms of heat exchange: biophysics and physiology
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Gagge, A.P., Gonzalez, R.R., 2011. Mechanisms of heat exchange: biophysics and physiology. Comprehensive Physiology, 45e84.
Ergonomics of the Thermal Environment-determination and Interpretation of Cold Stress when Using Required Clothing Insulation (IREQ) and Local Cooling Effects. International Organization for Standardization
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Huang, J., McCullough, E.A., 2003. Evaluation of Heat Loss Models for Predicting Temperature Ratings of Sleeping Bags. Technical Report 03e80. Institute for Environmental Research, Kansas State University, Manhattan, KS. ISO 11079, 2007. Ergonomics of the Thermal Environment-determination and Interpretation of Cold Stress when Using Required Clothing Insulation (IREQ) and Local Cooling Effects. International Organization for Standardization, Geneva. ISO 15831, 2004. Clothing-physiological Effects-measurement of Thermal Insulation by Means of a Thermal Manikin. International Organization for Standardization, Geneva.
Issues Concerning the EN 13537 Sleeping Bag Standard. An invited paper presented to the Outdoor Industry Association (OIA)
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McCullough, E.A., 2009. Issues Concerning the EN 13537 Sleeping Bag Standard. An invited paper presented to the Outdoor Industry Association (OIA), Boulder, CO, available from: http://www.outdoorindustry.org/pdf/ EN13537Mccullough062209.pdf (accessed 07.01.12.).
Evaluation of EN 13537 and other models for predicting temperature ratings of sleeping bags
  • E A Mccullough
  • J Huang
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McCullough, E.A., Huang, J., Jones, B.W., 2005. Evaluation of EN 13537 and other models for predicting temperature ratings of sleeping bags. In: Holmér, I, Kuklane, K, Gao, C. (Eds.), Proceedings of the 11th International Conference on Environmental Ergonomics (ICEE), May 22e26, 2005, Ystad, Sweden, pp. 425e428.
The effect of auxiliary products on the insulation provided by sleeping bag systems
  • E A Mccullough
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McCullough, E.A., Zuo, J., Huang, J., 2009. The effect of auxiliary products on the insulation provided by sleeping bag systems. In: 2009 ITAA (International Textile and Apparel Association) Proceedings, October 28e31, 2009, Washington, USA, #66.