Abstract
The present study investigated the effect of a uncompensable heat stress (UHS) situation on heat tolerance, physiological and perceptual parameters in females and males wearing firefighting personal protective equipment (PPE) during a modified heat occupational tolerance test (HOTT). Twenty-four healthy, physically fit adults, 12 females and 12 males, performed a modified HOTT of 60 minutes walking on a treadmill in a climatic chamber at an ambient temperature of 40 °C. Physiological and perceptual variables were measured. There were no differences between groups in heat tolerance, rectal temperature (Trec), heart rate (HR), mean skin temperature (Tskin) physiological strain index (PhSI), percent body mass loss, thermal sensation (TS) or rate of perceived exhaustion (RPE). Males displayed a higher sweat rate (SR) and body mass loss. Males also had a higher oxygen consumption (V̇O2) and minute ventilation (V̇E). In conclusion, our findings indicate that males and females do not differ in their physiological and perceptual responses in a UHS situation in which both non evaporative and evaporative processes of heat dissipation are impaired.