Adapting to the Heat: Does Sex or Hormone Status Matter?

Ovarian hormones modulate peripheral and central thermoeffector thresholds, potentially shifting the thermal load required to elicit robust adaptations. Chronic heat alleviation strategies aim to induce heat adaptation (HA) through structured exposure to hot environments, either via natural acclimatisation or heat acclimation in controlled settings such as heat chambers. HA elicits physiological adaptations that improve tolerance to heat stress, including lower resting core temperature, earlier onset of sweating and vasodilation, and increased sweat rate. However, interpretation in female participants is complicated by ovarian hormone fluctuations. Despite clear sex differences in thermoregulatory responses, females remain under-represented in HA research, limiting mechanistic understanding. Available evidence suggests females often require greater or prolonged thermal stimuli to achieve the same adaptations as males, and strategies developed in male cohorts may not reduce physiological strain in females. Menstrual cycle phase and hormonal contraceptive use can further influence adaptation. In this talk, Jessica will share mechanistic evidence on female-specific adaptation, highlighting hormonal modulation, cardiovascular and thermoeffector adjustments, and protocol-dependent responses. Attendees will gain insight into the influence of ovarian hormones on heat adaptation and the importance of designing individualised, evidence-based HA strategies for females.