THERMOREGULATION IN WOMEN DURING UNCOMPENSABLE HEAT-STRESS

1. The purpose of this investigation was to quantify heat exchange in women during exercise under conditions of uncompensable heat stress. The women were studied in the early follicular phase of the menstrual cycle. 2. The average exercise time was 52 +/- 13 minutes, end exercise mean body temperature was 38.4 +/- 0.4 degrees C, and end exercise heart rate was 169 +/- 14 b min(-1) during these follicular phase experiments. 3. Net heat flow (M(sk)) during exercise averaged 193 +/- 30 W m(-2), the change in body temperature was 0.03 +/- 0.01 degrees C min(-1), evaporative heat loss through the clothing (E(cl)) averaged 139 +/- 46 W m(-2), which was 45 +/- 14% of the sweating rate. 4. Women exercising during uncompensable heat stress during the early follicular phase of their menstrual cycles exercised for a similar duration as that predicted for men by our Institute's heat strain model. Currently, we do not generalize these conclusions to all phases of the menstrual cycle.