| Hot and humid environment is an extreme thermal environment of modernsociety. Exposure to hot and humid environment poses great threats on workersoccupational health and personal safety. It is urgent that an intuitive and reliableevaluation method be set to realize the maximum protection of human security underhot and humid environment. Influence of hot and humid environment on humanbody’s physiological systems, response trends of related physiological indices andchanges of subjective consciousness symptoms are the main factors of evaluatingbody safety under heat exposure. Controllable and feasible research methods of therelationship between human body and thermal environment are important basis forevaluating body safety under heat exposure. Through the subjective experiments,exploration research on human body physiological response and experimentalresearch method under hot and humid environment was performed.A test chamber of extreme environment was constructed. The environmentalparameters were set as four conditions: comfortable environment with dry bulbtemperature25℃and relative humidity50%, hot and humid environments with drybulb temperature30℃,35℃,40℃and relative humidity90%. Health collegestudents with no heat acclimatization were chosen as experimental subjects. Themedium and heavy physical labors were simulated by treadmill. A set of humanphysiological information monitoring system with high speed and multi-channel wasestablished. The subjects were required to complete120-minute experiments of sit-in,3.5km/h and5.5km/h treadmill running, respectively. The experiments suspendedwhen subjects complained of reaching tolerance limit. During the experiments,physiological information was real-time acquisition and subjective questionnaireswere filled out.The results confirm the significant influence of hot and humid environment onhuman physiology. The variations of heart rate, oral temperature, skin temperature,metabolic rate, heat storage rate, blood oxygen saturation and surfaceelectrocardiogram were obtained. The influence degrees of hot and humidenvironment made on subjective consciousness were analyzed.The sensitive parameters followed by metabolic rate, heart rate, skin temperature,oral temperature and heat storage rate. The suggested tolerance limits of sensitivephysiological parameters and consciousness state were given out. The metabolismmathematical model and heat storage mathematical model were established for simplifying calculation.Metabolic rate, arterial oxygen saturation and electrocardiogram changes indicatethe O2consumption increased with the increasing temperature, and the O2deliverydecreased with the increasing temperature. Hot and humid environment madesignificant influence on human body O2consumption and O2delivery.The resultsconfirm that the experimental research method is suitable for the study on relationshipbetween human body and extreme environment. |
