View clinical trials related to Heat Stress Disorders.
Filter by:Repeated exposure to heat in a laboratory setting (acclimation) elicits a range of adaptations, which reduce heat illness risk and increase work capacity in the heat. Traditional approaches to heat acclimation require daily heat exposures of 1 to 2 hours over ~7 to 10 consecutive days. Heat acclimation approaches which reduce the number of days to achieve acclimation may have utility. The primary purpose of the proposed research is to determine whether it is possible to achieve a similar degree of heat acclimation to that seen with a traditional longer-term heat acclimation approach by increasing the frequency of heat exposure, utilising multiple daily heat exposures over a smaller number of days. Secondary aims of the research are to examine whether heat acclimation provides cross-adaptation to a hypoxic stressor and whether heat acclimation improves aerobic fitness.
The aim of this initial investigational study is to compare the effect of desloratadine on the inflammatory responses to heat stress in firefighters exercising in their personal protective equipment.
The arduous nature of military training and operations require personnel to encounter high heat load, e.g., during intense physical exertion, particularly in the heat. These conditions reduce operational effectiveness and expose personnel to a risk of incapacitation and death from exertional heat illness (EHI). The primary aim of this study is to compare putative 'chronic' EHI risk factors between a cohort who have suffered a history of EHI and a control cohort with no EHI history. The secondary aim is to examine the influence of these EHI risk factors on thermoregulation during a standard heat tolerance assessment.
The purpose of this study is to measure fatigue and indicators of acute kidney injury during consecutive days of work in a hot environment.
Women are often understudied in thermal physiology research, leaving recommendations for Soldier safety and performance in hot conditions based largely on data collected in men. Female sex hormones estradiol and progesterone clearly have non-reproductive physiological effects, including influences on thermoregulatory and cardiovascular function. However, mechanisms of differing physiological adaptations to repeated heat exposure (i.e., heat acclimation) as a function of reproductive hormone status have yet to be investigated in a systematic way. Understanding possible sex differences in adaptation or mechanisms for adaptation during heat acclimation is important to ultimately optimize interventions to maximize soldier health and safety during training and deployment in the heat. Our goals in the present study are to evaluate physiological and biophysical responses to a standard heat acclimation protocol in a group of young, healthy men and women. Thirty individuals (n=10 males, n=10 women with a low hormonal status (i.e. early follicular phase), n=10 women with a high hormonal status (i.e. midluteal phase)) will complete 10 consecutive days of exercise (treadmill walking: 3.1 mph/2% grade) in the heat (40°C /40% relative humidity) up to 3hr per day. Changes in core temperature, heart rate, and sex hormones will be assessed to examine differences in thermoregulatory response to heat acclimation.
The primary purpose of the proposed study is to evaluate the effects of a topical sodium bicarbonate lotion (PR Lotion, AMP Human, Park City, UT) on measures of hydration status and fluid balance in humans when exposed to the heat while resting and during light/moderate aerobic exercise. A secondary purpose is to examine these same effects with two differing dosage patterns of the lotion. A tertiary purpose is to investigate the effect of an amino acid rehydration beverage in comparison to a placebo on measurements of hydration, subjective assessments of stress, and vestibular as well as musculoskeletal measures of fatigue for up to 24-hours after the completion of both passive and exertional heat stress within a dehydrated state.
Severe heat strain arising from intense physical work under climate conditions that does not allow sufficient heat dissipation may lead to heat stroke. This severe conditions is hypothesized to be secondary to increased gut permeability and leakage of bacterial toxins across the gut membrane, stimulating a systematic inflammatory response and associated organ injury. Repeated such sub-clinical increases in gut permeability has been suggested to contribute to the high burden of chronic kidney disease among heat-stressed workers. Many marathon runners experience a transient increase in kidney injury biomarkers while running. Probiotics have been studied as a way to decrease gut permeability and reduce systemic inflammation in many settings, including in athletes . However, no study has measured renal outcomes among workers or athletes performing strenuous activity. This is of interest as it could test the hypothesis that gut-induced inflammation is a driver of kidney injury during heat stress, and could point to a possible intervention to add on to efforts to relieve heat strain. In the present study, recreational or professional runners will be randomized to take a probiotic supplement or placebo during a 4 week period preceding a strenuous physical exercise (minimum 21 km run). Urine samples will be taken before and after the run, and analyzed for markers of renal injury and inflammation.
The arduous nature of military training and operations require personnel to encounter high heat load, e.g., during intense physical exertion, particularly in the heat. These conditions reduce operational effectiveness and expose personnel to a risk of incapacitation and death from exertional heat illness (EHI). The aim of this study is to examine traditional and novel risk factors that may increase thermal strain and EHI likelihood in military recruits undergoing strenuous physical exercise.
This is primarily an experimental study investigating methods of temperature measurement / heat strain detection. In the calibration study, there are different skin temperature sensor types, and in the prediction study there are different methods for determining heat strain, including conventional methods (rectal, gastro-intestinal), the development of a prediction model, and an index based on heart rate variability.
The study aims to investigate the effects of including regular heat therapy when included to exercise. Specifically, participants in the sauna intervention group will undergo 15 minutes of sauna exposure immediately after a 50-minute session of exercise, 3 times a week, while participants in the exercise intervention group will follow only the same exercise protocol. The 50-minute exercise session consists of 20 minutes of moderate intensity strength exercise, followed by 30 minutes of moderate-vigorous aerobic exercise on stationary bikes. This exercise intervention protocol was selected in order to meet and adhere to the recommended physical activity guidelines.