Body mapping of thermoregulatory and perceptual responses of males and females running in the cold

• Females exhibited lower Tsk¯and regional Tsk than males.
• Tsk distribution pattern was similar between males and females.
• Tsk distribution was not associated with the distribution of skinfold thickness, except for the anterior torso.
• Thermal sensation distribution was associated with Tsk distribution during exercise.

Thermoregulatory parameters during exercise are typically reported as global responses (Tcore and mean Tsk). In contrast, this study investigated regional skin temperatures (Tsk) over the body, in relation to regional skinfold thickness and regional perceptual responses for both sexes using a body-mapping approach. Nine males and nine females, of equivalent fitness, minimally clothed, ran for 40 min at 70% V̇O2max in a 10 °C, 50% rh, 2.8 m s−1 air velocity environment. Tsk was recorded by infrared thermography and processed to obtain population-averaged body maps. Rectal temperature and heart rate were monitored continuously throughout the running trial. Skinfold thickness was obtained for 24 sites and thermal sensation votes for 11 body regions.Males and females had similar rectal temperature, heart rate and regional sensations. Whole-body maps of Tsk highlighted the significantly lower regional Tsk for females (−1.6 °C overall, p<0.01). However, the distribution of Tsk across the body was similar between sexes and this was not correlated with the distribution of skinfold thickness, except for the anterior torso. On the other hand, regional thermal sensation votes across the body were correlated with Tsk distribution during exercise (females: r=0.61, males: r=0.73, p<0.05), but not at rest.Our thermographic results demonstrate the similar Tsk distribution for active males and females during submaximal running in the cold, though shifted to a lower mean value for females. This Tsk distribution was associated with regional sensations but not with local fat thickness. The described body-mapping approach can have implications in physiological modelling and clothing design.