WELLS, CHRISTINE L. Responses of physically active and acclimatized men and women to exercise in a desert environment.Med. Sci. Sports Exercise, Vol. 12, No. 1, pp. 9–13, 1980. In most studies of physiological responses of men and women to exercise in the heat, the subjects are unacelimatized and the females are unaccustomed to strenuous physical activity. In this investigation, 5 men and 6 women known to be physically active in an outdoor hot-dry environment were studied in a temperate environment (Tdb= 23C, WBGT = 18C) and in an outdoor desert environment (Tdb=39C, WBGT=29C) during rest and exercise at 50% Vo2max. No differences between the groups occurred in Vo2, HR or Trein either environment. Of greatest interest was that no differences occurred in evaporative weight losses, sweating rates, or % body weight losses in the heat. It was concluded that (1) women accustomed to exercise in a desert climate are able to substantially increase their sudorific response, and (2) that acclimatized male and female subjects of similar aerobic capacity have comparable responses to rest and exercise in a desert environment.