EVALUATION ON HEAT TOLERANCE BY PHYSIOLOGICAL HEAT STRESS INDEX

摘要

Heat exposure bring severe hazard to human bodies. At present, limited simple and reliable heat evaluation index can be applied in actual working environment. By experiments, the heat stress and heat tolerance of 148 male volunteers were examined under different climatic conditions in a stainless steel climatic chamber. The conditions were 30 to 40 dry bulb temperature and 40 to 80 percent relative humidity. The subjects, aged from 19 to 26 years old, performed various activities at the metabolic heat of 175, 349 and 580 W, respectively. The exposure durations and resulting heat stress were determined by measuring oral temperature, skin temperature, heart rates, blood pressure and sweating responses. The physiological heat stress index (PHSI) was proposed and applied for heat tolerance evaluation, which can definitely reflect body heat exposure condition. Also, reliable and safe range of PHSI was achieved to instruct works to control the actual heat exposure.