Mike Tipton

University of Portsmouth · School of Sport Exercise & Health Science

New Findings What is the topic of this review? This review concerns human responses to extreme environmental stresses. What advances does it highlight? This review highlights the following factors: the relatively limited and varying value of adaptation; the value of research in this area to inform other medical conditions; the physiological pathway...

Open water swimming (OWS), either ‘wild’ such as river swimming or competitive, is a fast growing pastime as well as a part of events such as triathlons. Little evidence is available on which to base high and low water temperature limits. Also, due to factors such as acclimatisation, which disassociates thermal sensation and comfort from thermal st...

Cold water submersion can induce a high incidence of cardiac arrhythmias in healthy volunteers. Submersion and the release of breath holding can activate two powerful and antagonistic responses: the 'cold shock response' and the 'diving response'. The former involves the activation of a sympathetically driven tachycardia while the latter promotes a...

Adaptation to an environmental stressor is usually studied in isolation, yet these stressors are often encountered in combination in the field, an example being cold and hypoxia at altitude. There has been a paucity of research in this area, although work with rodents indicates that habituation to repeated short cold exposures has a cross-adaptive...

Background Cold water swimming is growing in popularity, especially among women. We have previously reported that women felt that cold water swimming helps with their menstrual and menopause symptoms. But little is known about the habits of women who cold water swim. Objectives To determine the habits of women who cold water swim. Design This was...

Background The RNLI “Float to Live” campaign is based on research conducted in indoor pools with experienced open water swimmers. Study 1 investigated whether the RNLI “Float to Live” guidance would enable less experienced individuals to float in realistic open water conditions. Study 2 examined the separate effects of practice and coaching on floa...

This article seeks to explore the way in which key, specifically situated actors within the UK water rescue community understand and perceive challenges relating to navigating policy and practical challenges inherent to their role. Utilizing Lipsky's notion of the ‘street level bureaucrat’, focus groups and interviews were undertaken with water res...

High altitude residents have a lower incidence of type 2 diabetes mellitus (T2DM). Therefore, we examined the effect of repeated overnight normobaric hypoxic exposure on glycaemic control, appetite, gut microbiota and inflammation in adults with T2DM. Thirteen adults with T2DM [glycated haemoglobin (HbA1c): 61.1 ± 14.1 mmol mol⁻¹; aged 64.2 ± 9.4 y...

Background The RNLI “Float to Live” campaign is based on research conducted in indoor pools with experienced open water swimmers. Study 1 investigated whether the RNLI “Float to Live” guidance would enable less experienced individuals to float in realistic open water conditions. Study 2 examined the separate effects of practice and coaching on floa...

Background: Offshore wind technicians (WTs) have been identified as having an occupation with high physical demands. Objective: To characterise the physical demands of WTs, during the working day and when performing casualty rescues. Methods: Data collection consisted of two components. Component A, 14 WTs (n = 13 male, 1 female) were monitore...

BACKGROUND: Offshore wind technicians (WTs) have been identified as having an occupation with varying physical demands. Therefore, in order to assess WTs capability to undertake the job, there was a need to identify and quantify the physical requirements of the essential tasks. OBJECTIVE: To establish the essential tasks and quantify the associated...

Objective This study aimed to determine how women felt cold water swimming affected their menstrual and perimenopausal symptoms. Study design An online survey that asked women who regularly swim in cold water about their experiences. The survey was advertised for 2 months on social media. Questions related to cold water swimming habits and menstru...

Objective This study aimed to determine how women felt cold water swimming affected their menstrual and perimenopausal symptoms. Study design An online survey that asked women who regularly swim in cold water about their experiences. The survey was advertised for 2 months on social media. Questions related to cold water swimming habits and menstrua...

Objective: Drowning is a leading cause of death. The World Health Organization (WHO) and United Nations (UN) emphasise the need for population-level data-driven approaches to examine risk factors to improve water safety policies. Weather conditions, have the potential to influence drowning risk behaviours as people are more likely to spend time aro...

Objectives: Repeated hot water immersion (HWI) can improve glycaemic control in healthy individuals, but data are limited for individuals with T2DM. The present study investigated whether repeated HWI improves insulin sensitivity, inflammatory status, reduces plasma ([extracellular heat shock protein 70]) [eHSP70] and resting metabolic rate (RMR)....

Heat acclimation/acclimatisation (HA) mitigates heat-related decrements in physical capacity and heat-illness risk and is a widely advocated countermeasure for individuals operating in hot environments. The efficacy of HA is typically quantified by assessing the thermo-physiological responses to a standard heat acclimation state test (i.e. physiolo...

Astronauts in microgravity experience multi-system deconditioning, impacting their inflight efficiency and inducing dysfunctions upon return to Earth gravity. To fill the sex gap of knowledge in the health impact of spaceflights, we simulate microgravity with a 5-day dry immersion in 18 healthy women (ClinicalTrials.gov Identifier: NCT05043974). He...

Globally, drowning is the third leading cause of unintentional injury death, accounting for 7% of all injury-related deaths. This study aimed to examine the spatial clustering in UK drowning incidents. Data were obtained from the Water Incident Database (WAID) (1/1/2012–31/12/19). We examined spatial clustering of intentional and unintentional drow...

Previous research has shown that ≤60 min hypoxic exposure improves subsequent glycaemic control, but the optimal level of hypoxia is unknown and data are lacking from individuals with overweight. We undertook a cross-over pilot feasibility study investigating the effect of 60-min prior resting exposure to different inspired oxygen fractions (CON FI...

We convened an expert panel to develop evidence-based guidelines for the evaluation, treatment, and prevention of nonfreezing cold injuries (NFCIs; trench foot and immersion foot) and warm water immersion injuries (warm water immersion foot and tropical immersion foot) in prehospital and hospital settings. The panel graded the recommendations based...

Plasma biomarkers of inflammation, oxidative stress, endothelial function and damage were examined in 16 individuals with chronic NFCI (NFCI) and matched control participants with (COLD, n = 17) or without (CON, n = 14) previous cold exposure. Venous blood samples were collected at baseline to assess plasma biomarkers of endothelial function (nitra...

The aim of this study was to compare peripheral sensory neural function of individuals with non‐freezing cold injury (NFCI) with matched controls (without NFCI) with either similar (COLD) or minimal previous cold exposure (CON). Thirteen individuals with chronic NFCI in their feet were matched with the control groups for sex, age, race, fitness, bo...

The impact of non‐freezing cold injury (NFCI) on peripheral vascular function was investigated. Individuals with NFCI (NFCI group) and closely matched controls with either similar (COLD group) or limited (CON group) previous cold exposure were compared (n = 16). Peripheral cutaneous vascular responses to deep inspiration (DI), occlusion (PORH), loc...

When exposed to ambient temperatures that cause thermal discomfort, a human's behavioral responses are more effective than autonomic ones at compensating for thermal imbalance. These behavioral thermal responses are typically directed by an individual's perception of the thermal environment. Perception of the environment is a holistic amalgamation...

Climate change means people will be working and living in more extreme conditions In high-income countries, people spend most of their time indoors and have lost their thermal resilience An understanding of human physiology enables us to characterise the impact of climate change on human health and productivity, and design environments that help ma...

When exposed to ambient temperatures that cause thermal discomfort, a human’s behavioral processes are more effective than autonomic ones. These behavioral thermal responses are typically directed by an individual’s perception of the thermal environment. Existing evidence suggests that perception is a holistic amalgamation of human senses, and that...

The prediction of survival time for those immersed in water remains a key element in the function of search and rescue organisations around the globe. The data on which such predictions are made come from laboratory studies and actual incidents. The UK National Immersion Incident Survey (UKNIIS) represents one of the largest surveys undertaken in t...

International Journal of Exercise Science 15(6): 1295-1305, 2022. Since the inclusion in the Olympic Games (2008), open swimming races have attracted greater media attention and, therefore, have a greater number of practitioners, especially in Brazil, an extremely favorable country for this sport. However, increasing reports of fatal incidents in o...

Background This study evaluated cognitive workload in soldiers undertaking a long duration march wearing different loads. Methods Military participants (n=12 men and n=10 women) performed four 3-hour loaded marches (12.25 km at 4.9 km/hour) wearing either 21 kg, 26 kg, 33 kg or 43 kg. During the march, accuracy and response time were measured usin...

Introduction The volume, nature, and risks of paragliding are poorly quantified. More comprehensive understanding, including incident rates allowing comparison to similar disciplines, will help direct and appraise safety interventions. Methods Paraglider pilots were surveyed regarding experience, incidents, recordkeeping, and risk perception. The...

There is a need to rapidly screen individuals for heat strain and fever using skin temperature (Tsk) as an index of deep body temperature (Tb). This study’s aim was to assess whether Tsk could serve as an accurate and valid index of Tb during a simulated heatwave. Seven participants maintained a continuous schedule over 9-days, in 3-day parts; pre-...

A person, usually a child or young adult, dies by drowning every 90 seconds around the planet. Most drowning prevention initiatives do not assess the efficacy of the intervention. In this study, thirteen- to fourteen-year-olds had their level of water safety knowledge (covering cold shock, rips and tides) assessed before, just after, and 3-6 months...

Internationally, drowning is a leading cause of accidental death that features in many legal cases. In these cases, possible mitigations and the ‘pain and suffering’ in terms of the duration and subjective experience of drowning are often pivotal in determining levels of compensation and outcome. As a result, there is a requirement to understand th...

Cold injury can result from exercising at low temperatures and can impair exercise performance or cause lifelong debility or death. This consensus statement provides up-to-date information on the pathogenesis, nature, impacts, prevention, and treatment of the most common cold injuries.

Background Death by drowning is a leading cause of accidental death in the United Kingdom (UK) and worldwide. The World Health Organization (WHO) states that effective documentation of drowning is required to describe drowning frequency and to underpin effective drowning prevention intervention, thus improving the quality of data describing drownin...

It has long been claimed that non-wetsuit cold water swimming (CWS) benefits health (1), and anecdotally cold-water swimmers claimed to suffer fewer and milder infections, though this was not directly measured. A boost to immunity is biologically plausible: stress hormones are released during cold-water immersion (2), and short-term stress may read...

INTRODUCTION: The paragliding reserve parachute system is safety-critical but underused, unstandardized, and known to fail. This study aimed to characterize reserve parachute deployment under radial acceleration to make recommendations for system design and paraglider pilot training. METHODS: There were 88 licensed amateur paraglider pilots who wer...

Background. Death by drowning is a leading cause of accidental death in the United Kingdom (UK) and worldwide. The World Health Organization (WHO) states that effective documentation of drowning is required to describe drowning frequency and to underpin effective drowning prevention intervention, thus improving the quality of data describing drowni...

Type 2 diabetes mellitus (T2DM) is characterized by chronic hyperglycemia and progressive insulin resistance, leading to macro and microvascular dysfunction. Passive heating has potential to improve glucose homeostasis and act as an exercise mimetic. We assessed the effect of acute passive heating before or during an oral glucose tolerance test (OG...

Around the planet, in many different scenarios, skin temperature is being used as a surrogate measure of deep body (core) temperature in the assessment of whether an individual is infected with the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2), which causes the coronavirus disease (Covid‐19, or C‐19), as indicated by the presence of...

We investigated whether an 11-day heat acclimation programme (HA) enhanced endurance performance in a temperate environment, and the mechanisms underpinning any ergogenic effect. Twenty-four males (V̇O2max: 56.7±7.5 mL·kg⁻¹·min⁻¹) completed either: i) HA consisting of 11 consecutive daily exercise sessions (60-90 minutes·day⁻¹; n=16) in a hot envir...

This short review was prompted by The Physiological Society's recent online symposium on variability. It does not deal with a specific methodology, but rather with the myth that certain environmentally-induced clinical conditions can be identified, quantified, simplified and monitored with a single methodology. Although this might be possible with...

Surveillance is key to the lifesaving capability of lifeguards. Experienced personnel consistently display enhanced hazard detection capabilities compared to less experienced counterparts. However, the mechanisms which underpin this effect and the time it takes to develop these skills are not understood. We hypothesized that, after one season of ex...

New findings: What is the central question of this study? What is the physiological interpretation of SpO2 fluctuations observed during normobaric hypoxia in healthy individuals? What is the main finding and its importance? There is a significant flow of information between SpO2 and other cardio-respiratory time-series during graded hypoxia. Analy...

New findings: What is the central question of this study? Does recreational cold exposure result in cold sensitivity and is this associated with endothelial dysfunction and impaired sensory thermal thresholds? What is the main finding and its importance? Previous cold exposure was correlated with foot cold sensitivity which may indicate the develo...

New findings: What is the topic of this review? The effect of extreme environments on the visual system. What advances does it highlight? The manner in which environmental stressors directly and indirectly affect the eye and vision. Abstract: Much is known about the physiology and anatomy of the eye. Much less is known about the impact of differ...

Women can now serve in ground close combat (GCC) roles, where they may be required to operate alongside men in hot environments. However, relative to the average male soldier, female soldiers are less aerobically fit, with a smaller surface area ( AD ), lower mass (m) with higher body fat and a larger AD /m ratio. This increases cardiovascular stra...

Background: The study is the first to evaluate the effects of graded normobaric hypoxia on SpO2 variability in healthy individuals. Materials and Methods: Twelve healthy males (mean [standard deviation] age 22 [4] years) were exposed to four simulated environments (fraction of inspired oxygen [FIO2]: 0.12, 0.145, 0.17, and 0.21) for 45 minutes, in...

Background: Dehydration is common in hospitals and is associated with increased mortality and morbidity. Clinical assessment and diagnostic measures of dehydration are unreliable. We sought to investigate the novel concept that individuals might control their own intravenous rehydration, guided by thirst. Methods: We performed a single-blind, co...

Objective: To determine the thermal demand of simulated Flood Rescue tasks and impacts on performance. Methods: Ten participants undertook two simulations: ‘Cold’ (4 °C)-participants stood in knee height moving water (4.8km·h⁻¹), with simulated wind and rain for 60 min. ‘Warm’ (20 °C)-participants performed 6x7 min walking in knee height moving wat...

This study investigated the ergonomics of three simulated 120 m vertical ladder ascents and differences between novice (NC) and experienced climbers (EC). Seven EC and 10 NC undertook three 120 m climbs; comprising of four 30 m climbs. Ascending 120 m was reported as a high physical demand, supported by high peak HRs (~173 b.min-1 across the three...

The impact of environmental conditions is often overlooked in sport, where the pre-occupation is generally with nutrition and training. However, inappropriate preparation and strategy for the thermal conditions of an event can not only significantly impact on performance, but it can also threaten athlete health and safety. Thus, those organising, s...

A s the popularity of open water swimming continues to grow, so do the number of people 'pushing the boundaries' at the extremes of distance and temperature. We spoke to some leading experts on cold water swimming and gained some advice about the effects it has on the body, how to look out for signs of hypothermia and a few general pointers if you'...

Ectodermal dysplasia (ED) is a rare genetic disorder occurring as a consequence of gene mutations that code for the ectoderm of the developing embryo and results in numerous disorders of varying severity. The lack of functioning sweat glands in those affected with ED leads to high infant mortality and frequent complaints of hyperthermia. Temperatur...

The impact of environmental conditions is often overlooked in sport, where the pre-occupation is generally with nutrition and training. However, inappropriate preparation and strategy for the thermal conditions of an event can not only significantly impact on performance, but it can also threaten athlete health and safety. Thus, those organising, s...

INTRODUCTION: Paragliding is an emerging discipline of aviation, with recreational pilots flying distances over 100 km. It remains risky. Accidents typically relate to pilot error rather than equipment failure. We measured cognition and physiological responses during simulated flight, to investigate whether errors might be due to pilot impairment,...

PURPOSE: To develop a Physical Employment Standard (PES) for the British Royal Air Force Regiment (RAF Regt). METHOD: Twenty-nine RAF Regt personnel completed eight critical tasks wearing Combat Equipment Fighting Order (31.5 kg) while being monitored for physical and perceptual effort. A PES was developed using task simulations, measured on 61 inc...

Physiology is the “science of life” and, as physiologists, we are interested in the function and survival of diverse lifeforms including humans. The Physiological Society's recent “Extreme Environmental Physiology” meeting addressed the impact of the external environment on human physiology – fascinating papers from this event will appear in Experi...

This narrative review discusses the evidence relevant to key aspects of drowning, which is defined by the World Health Organization as the process of respiratory difficulty caused by submersion/immersion in liquid. The length of time the victim is submerged is a key factor in survival and neurologic damage. Although respiratory distress and hypoxia...

This narrative review discusses the evidence relevant to key aspects of drowning, which is defined by the World Health Organization as the process of respiratory difficulty caused by submersion/immersion in liquid. The length of time the victim is submerged is a key factor in survival and neurologic damage. Although respiratory distress and hypoxia...

Background: To establish whether an organization has a valid Physical Employment Standard (PES), it is important to determine those aspects of the job that are critical to operational success. Objective: To determine the tasks of the Offshore Wind Industry (OWI) and whether the ability to undertake these tasks is adequately assessed. Methods:...

Background: If current population and health trends continue, workplace demographics will look significantly different by the turn of the century. Organizations will no longer have a steady pipeline of younger workers and will likely need to rely on older workers to remain competitive in the global marketplace. The future multi-generational workfo...

New findings: What is the central question of this study? What are the mechanisms responsible for the decline in cognitive performance following exposure to acute normobaric hypoxia? What are the main findings and their importance? We found that 1) performance of a complex central executive task (n-back) was reduced FiO2 0.12; 2) there was a stron...