Experimental studies on the sexual and seasonal differences of the optimal thermal conditions.

Four male and four female students stayed for 90 min in a climate chamber with relative humidity of 60% and air velocity of less than 20 cm/sec at 16-24 degrees C effective temperature (E.T.) in summer and in winter. Measurements during the last period of exposure were used for the analysis. The neutral thermal sensation and the most comfortable sensation in sitting posture were obtained for both of males and females at 24 degrees C E.T. nude and 22 degrees C E.T. clothed both in summer and in winter. Light sedentary work, an addition test using a calculator, did not influence the relation between room temperature and the metabolic rate or the weighted averaged skin temperature, but the neutral point of thermal sensation and the most comfortable sensation were found at 20 degrees C E.T., 1--2 degrees C lower than at rest. Neither sexual nor seasonal differences was detected for the light work conditions. When the subjects performed light muscular work of 10 min of stepping up on and down from a 6 cm-high platform twice during the 90 min period, the relationship between room temperature and the metabolic rate or the weighted averaged skin temperature did not change by the work and the neutral thermal sensation and the most comfortable sensation were given at 18 degrees C E.T., 4 degrees C lower than at rest. Sexual and seasonal differences were not observed.