Effect Of Individual Differences On Physiological Responses Under Hot And Humid Environment

High thermal and humid environment widely existed in nature, industrial andmartial etc. environment. The high heat stress induced the workers inside a series ofheat responses. And excessive heat stress responses lead to potential threat and evenunrecoverable hazard for human health. Therefore, scholars have been devoting toresearches on human physiological responses to heat stress during heat exposure. Andthe researches on the effect of climate, work intensity, physical fitness andanthropometric characteristics on heat stress responses are included. By carrying onheat duration experiment, this study developed an exploratory research on the effectof physical fitness and anthropometric characteristics on human heat stress responses.A high thermal and humid environment chamber was used to simulate a mildclimate, a warm humid climate and a dry hot climate.20healthy volunteereduniversity students were selected to exercise at low and high intensity, respectively.And the intensity was set to the same relative level of maximal oxygen uptake(VO2max), which is25%VO2maxand45%VO2max, respectively. The oral temperature(Tor), skin temperature (Tsk), heart rate (HR) and sweat loss (SL) of subjects wasmeasured during heat exposure, as well as the heat tolerance time of subjects.The effect of physical fitness and anthropometric characteristics on physiologicalcharacteristics was analyzed in different climate and intensity. It was demonstratedthat among anthropometric characteristics, body weight (Wb), body surface area (BSA)and percentage of body fat (Fat%) etc. correlated with△Tco(increased Tor),△Tsk(increased Tsk),△HR (increased HR) and SL in different significant level in differentclimate and exercise intensity.By heat exposure experiment, the influences made by gender on humanphysiological heat stress responses were analyzed, as well as the gender difference inthe effect made by individual characteristics. The results showed that there weredifferent heat stress responses between genders, and the influential individualcharacteristics of females were different from those of males.The effects of gender, anthropometric characteristics, and physical fitness onhuman heat tolerance time were analyzed. It is confirmed that VO2maxmakesignificant effects on heat tolerance time in warm wet climate and hot dry climate, and difference in heat tolerance time between genders.Based on theoretical research, a body characteristic index (BCI), integratedanthropometric characteristics and physical fitness, was developed, and corrected andverified by experiment data. BCI can evaluate the relative level of human heat stressresponses during heat exposure in a group of people, and predict the variance ofphysiological characteristics in the heat duration. This index was easily calculated andneeded no measurement of physiological characteristics. And the independence ofclimate and work intensity made it widely used.