Physiological responses of resting men and women in hot environment at 50°C

9 young males and 7 young females were used as subjects. Subjects were exposed to hot environment at 50°C in supine position for 61min after resting at 28°C for 30min. Rectal and mean skin. temperatures were measured during exposure. Increase in rectal temperature tended to be larger in male than in female, though the difference of increase in rectal temperature between both sexes was not significant statistically. In male subjects, increase in rectal temperature was correlated with body weight, body fat content, skinfold thickness, body surface area and body surface area-to-mass ratio. But, such relationships were not shown in female subjects. Oxygen uptake, heart rate and pulmonary ventilation were linearly correlated with rectal temperature for males and females. Relationship between rectal temperature and ventilatory equivalent was found only for 4 males. It was suggested that a part of the males showed increase in ventilatory equivalent as a response to hyperthermia.