Exposure limits of women in hot environment

The tolerance of six women to work in hot environments was examined under f our environmental conditions from 38 to 44 degrees C dry bulb temperature a nd 50 to 80 per cent relative humidity, ie., 32 to 36.5 degrees C effective temperature [ET (normal scale)] in a climatic chamber The subjects perform ed bicycle ergometric work at an intensity of 50 W and the exposure duratio n was determined by the cardiorespiratory, body temperature and sweating re sponses. At the limit of tolerance, the body coke temperature (T-cr) reache d over 38.5 degrees C and the heart rates attained a peak level (ie., about 172 beats/min). The total oxygen demand decreased significantly with highe r environmental load, particularly beyond 33.5 degrees C ET (N). While the tolerance time decrement was evident with the higher heat stress, on an ave rage, am increase or decrease of every liter of total oxygen demand was equ ivalent to a 0.8 min change in, the tolerance time. As such, the women volu nteers were not susceptible to heat; only in extreme hot situations beyond 33.5 degrees C ET (N), they had unacceptable levels of physiological and ps ychophysical reactions. Based on the distribution of tolerance time of the women in'aifferent exposure conditions, the safe exposure times were estima ted, which varied from 43 min [32.0 degrees C ET (N)] to 16 min [36.5 degre es C ET (N)].