Temperature regulation in young women

Abstract

Possible sexual differences in the regulation against acceptable heat loads were studied by exposing female and male subjects to rising ambient temperature, TA (1 hr at 25 C, then 6.6 C/hr to 45 C) or to steady TA (43.3 C for 3 hr). Women were studied during the menstrual, preovulatory, and postovulatory periods. Oral (TO) and skin (TS) temperatures, cutaneous opacity pulses, regional sweating rates, and weight losses were measured. During the menstrual and preovulatory periods, the thermoregulatory responses of women were similar to those of men except for slightly larger cutaneous opacity pulses and greater rates of weight loss in several of the male subjects. The TO, but not TS, was consistently higher in women during heat exposures in the postovulatory period. Of several possible explanations, a higher setting of the hypothalamic thermostat seems the more probable reason for the elevation of TO without a corresponding increase in weight loss, regional sweating, and cutaneous opacity pulses. In other respects there were no essential differences in temperature regulation attributable to sex. regional sweating; body temperatures; regional cutaneous vasodilatation; moderate heat loads; temperature regulation during the menstrual cycle Submitted on September 14, 1964