Thermophysiological responses to occupational heat stress during simulated wildland firefighting in females and males: influence of fitness and body composition
- 1ALFIS Research Group, Department of Physical Education and Sports, Instituto de Biomedicina (IBIOMED), Instituto de Investigación Biosanitaria de León (IBIOLEÓN), Universidad de León, León, Spain
Abstract
This study compared thermophysiological responses to prolonged exercise during prolonged occupational heat stress in female and male participants involved in wildland firefighting activities while wearing standard personal protective equipment. Twenty-two participants (11 females and 11 males) performed a graded exercise test followed by a prolonged submaximal protocol simulating wildfire suppression tasks in a controlled environment (30 °C, 30% relative humidity). Physiological responses, gastrointestinal temperature (Tg), chest skin temperature (Tskin), sweat production, and heat balance components were evaluated. Females exhibited higher mean values for most physiological variables, except rating of perceived exertion, which was higher in males. However, when responses were analyzed at matched relative exercise intensities, no meaningful sex-related differences were observed in Tg, whereas chest Tskin and heart rate remained higher in females. Body fat percentage was positively associated with Tg and chest Tskin (r=0.55 and 0.53), whereas VO2max was negatively correlated with Tg (r=−0.47). This relationship disappeared when VO2max was normalized to lean body mass. Heat dissipation pathways differed between groups: males showed greater evaporative heat loss, whereas females exhibited a greater contribution of dry heat exchange. These findings suggest that individual body composition and aerobic fitness may contribute to variability in thermophysiological strain during occupational uncompensable heat stress.
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BibTeX
@article{gutierrezarroyo2026thermophysiological,
title = {{Thermophysiological responses to occupational heat stress during simulated wildland firefighting in females and males: influence of fitness and body composition}},
author = {Jorge Gutiérrez-Arroyo and Belén Carballo-Leyenda and Fabio García-Heras and Juan Rodríguez-Medina and Jose A. Rodríguez-Marroyo},
journal = {Frontiers in Physiology},
year = {2026},
month = oct,
doi = {10.3389/fphys.2026.1936332},
url = {https://doi.org/10.3389/fphys.2026.1936332},
note = {CC BY},
}
RIS
TY - JOUR
TI - Thermophysiological responses to occupational heat stress during simulated wildland firefighting in females and males: influence of fitness and body composition
AU - Jorge Gutiérrez-Arroyo
AU - Belén Carballo-Leyenda
AU - Fabio García-Heras
AU - Juan Rodríguez-Medina
AU - Jose A. Rodríguez-Marroyo
PY - 2026
DA - 2026/10/27
JO - Frontiers in Physiology
DO - 10.3389/fphys.2026.1936332
UR - https://doi.org/10.3389/fphys.2026.1936332
AB - This study compared thermophysiological responses to prolonged exercise during prolonged occupational heat stress in female and male participants involved in wildland firefighting activities while wearing standard personal protective equipment. Twenty-two participants (11 females and 11 males) performed a graded exercise test followed by a prolonged submaximal protocol simulating wildfire suppression tasks in a controlled environment (30 °C, 30% relative humidity). Physiological responses, gastrointestinal temperature (Tg), chest skin temperature (Tskin), sweat production, and heat balance components were evaluated. Females exhibited higher mean values for most physiological variables, except rating of perceived exertion, which was higher in males. However, when responses were analyzed at matched relative exercise intensities, no meaningful sex-related differences were observed in Tg, whereas chest Tskin and heart rate remained higher in females. Body fat percentage was positively associated with Tg and chest Tskin (r=0.55 and 0.53), whereas VO2max was negatively correlated with Tg (r=−0.47). This relationship disappeared when VO2max was normalized to lean body mass. Heat dissipation pathways differed between groups: males showed greater evaporative heat loss, whereas females exhibited a greater contribution of dry heat exchange. These findings suggest that individual body composition and aerobic fitness may contribute to variability in thermophysiological strain during occupational uncompensable heat stress.
SN - 1664-042X
ER -