View clinical trials related to Heat Exposure.
Filter by:The aim of this study was to determine the effect of hot application applied to the sacral region during first stage of labor on women's pain level and labor process.
The global populace is at growing risk of heat-related illness due to climate change and accompanying increases in the intensity and regularity of extremely hot temperatures. In heat-exposed persons, heat gain from the environment and metabolism initially exceeds the rate of heat dissipation from the skin. Heat is stored in the body, causing core and skin temperatures to rise, which in turn triggers autonomically mediated elevations in cutaneous blood flow and sweating to facilitate heat loss. If conditions are compensable, heat loss increases until it balances total heat gain. At this point, the rate of heat storage falls to zero (i.e., heat balance is achieved) and body temperature stabilizes, albeit at a level elevated from thermoneutral conditions. If, however, the maximal achievable rate of heat dissipation is insufficient to offset heat gain, conditions are uncompensable, and prolonged exposure will cause a continual rise in core temperature that can compromise health if left unchecked. The environmental limits of compensability (i.e., the temperatures/humidities above which heat balance can not be maintained) are therefore an important determinant of survival during prolonged heat exposure. Evaluating this limit and how it can be modified (e.g., by behavior or individual factors like age or sex) is an increasingly important and active field of study. Contemporary evaluations of the environmental limits of compensability utilize "ramping protocols" in which participants are exposed to increasing levels of temperature or humidity (in 5-10 min stages) while core temperature is monitored. It is generally observed that core temperature is relatively stable (or rises slightly) in the early stages of exposure but undergoes an abrupt and rapid increase as heat stress becomes more severe. The conditions (e.g., wet-bulb temperature or wet-bulb globe temperature) at this "inflection point" are taken as the limits of compensability. That is, it is assumed that inflection corresponds to the demarcation point, below which core temperature would remain stable for prolonged periods (theoretically indefinitely if hydration is maintained) but above which heat loss is insufficient to offset heat gain, causing core temperature to rise continuously. Despite the increasing use of these protocols, no study has clearly demonstrated their validity for identifying the environmental limits of compensability. The goal of this project is therefore to assess the validity of ramping protocols for determining the ambient conditions above which thermal compensation is not possible. Enrolled participants will complete four experimental trials in a climate-controlled chamber: one ramping protocol followed by three randomized fixed-condition exposures. In the ramping protocol, participants will rest in 42°C with 28% relative humidity (RH) for 70 min, after which RH will be increased 3% every 10 min until 70% RH is achieved. The core (esophageal) temperature inflection point will be determined. For the fixed-condition exposures, participants will rest in i) 42°C with RH ~5% below their individual inflection point (below-inflection condition), ii) 42°C with RH ~5% above their individual inflection point (above-inflection condition), and iii) 26°C with 45% RH (control condition). Comparing the rate of change in esophageal temperature between each fixed-condition exposure will provide important insight into the validity of ramping protocols for identifying the limits of compensability.
The goal of this clinical trial is to compare the efficiency of water biking training in hot (35°C) versus neutral (25°C) temperature water to elicite heat acclimation in healthy recreative athletes.
The purpose of this study is to examine the human thermoregulatory impact of applying a commercially available menthol gel (BioFreeze) to the skin prior to moderate intensity walking under heated conditions. Experimental Visits will consist of 30 min of treadmill walking at a moderate pace (3.5 mph, 5% grade) under hot conditions (38°C, 60%RH) and will be randomized and counterbalanced for BioFreeze or a hypoallergenic gel (control) application. Gels will be applied to areas commonly exposed during outdoor activity in warm conditions (shoulder to wrist, mid thigh to ankle). Accordingly, participants will wear shorts and a tank top shirt during exercise. Core temperature, skin temperature, galvanic skin response, laser doppler blood flow, and heart rate will be continuously recorded throughout the exercise bout via an integrated analog to digital converter. Sweat will be collected during exercise using commercially available absorbent patches. Thermal sensation will be assessed throughout exercise via the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) thermal sensation likert scale (cold to hot). Lastly, nude body weight will be recorded pre and post exercise for sweat rate determination. The BioFreeze and control trials will be separated by a 7-14 day washout period.
The purpose of this study is to examine the human thermoregulatory impact of applying a commercially available capsaicin gel to the skin prior to moderate intensity walking under heated conditions. Experimental Visits will consist of 30 min of treadmill walking at a moderate pace (3.5 mph, 5% grade) under hot conditions (38°C, 60%RH) and will be randomized and counterbalanced for capsaicin gel or a hypoallergenic gel (control) application. Gels will be applied to areas commonly exposed during outdoor activity in warm conditions (shoulder to wrist, mid thigh to ankle). Accordingly, participants will wear shorts and a tank top shirt during exercise. Core temperature, skin temperature, galvanic skin response, laser doppler blood flow, and heart rate will be continuously recorded throughout the exercise bout via an integrated analog to digital converter. Sweat will be collected during exercise using commercially available absorbent patches. Thermal sensation will be assessed throughout exercise via the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) thermal sensation likert scale (cold to hot). Lastly, nude body weight will be recorded pre and post exercise for sweat rate determination. The capsaicin and control trials will be separated by a 7-14 day washout period
The purpose of this research study is to evaluate the effects of a topical sodium bicarbonate lotion on physiological and psychological responses associated with hydration status and fluid balance in humans during passive heat stress. Currently, the ingestion of sodium has been an effective measure for improvements in fluid regulation and hydration status in humans. However, the investigators do not know its regulatory relationship with measurements of fluid balance when supplemented through the skin.
Investigators propose an intervention trial of a comprehensive education and treatment bundle designed to reduce morbidity and mortality associated with heat-related illness for low resource settings. Two set of interventions will be developed each for emergency department and for community/home. These interventions will be developed by an internal expert group and will be customized and implemented at the home and emergency department (ED) levels, will include evidence-based educational training guidelines for ED health providers as well as educational messages targeting home and community in Karachi, Pakistan.