Circadian and gender differences in skin temperature in militaries by thermography

Aim: The purpose of this study was to determine gender differences in skin temperature (TA) for 21 regions of interest (ROIs) of the body throughout the day in a military sample using infrared thermography. Methods: The T-sk of 20 male (23.2 +/- 2.9 yr) and 20 female (20.5 +/- 1.3 yr) Brazilian Air Force Military members were evaluated with four thermograms collected at 7:00 AM (T-sk7) and 7:00 PM (T-sk19) by a Fluke (R) thermal camera. The ROIs analyzed included the abdomen and bilateral anterior and posterior views of the hands, forearms, arms, thighs, and legs. Student's t-tests were performed on independent samples (alpha = 0.05). Results: With the exception of the hands, men's T-sk7 was significantly higher than that of women (p < 0.05). However, in the late evening (T-sk19), only the temperatures of the posterior side of the thigh and leg were significantly lower (p < 0.05) in women. Conclusions: In the early morning, men present a greater average T-sk than women across all evaluated ROIs; however, those differences disappear after 12 h, except for the posterior thighs and legs. The hands were the sole areas showing similar temperatures at both time points. (C) 2015 Elsevier B.V. All rights reserved.