Thermal, Cardiovascular, and Perceptual Responses to Exercise Heat Stress in Burn Survivors with and without Whole-Body Skin Wetting

Abstract

Introduction: Burn survivors experience higher rates of cardiovascular disease, diabetes, and stroke compared to non-burned individuals. These responses are due, in part, to lower exercise adherence perhaps associated with impaired thermoregulation. Improving heat dissipation and exercise “comfort” may minimize this barrier to exercise adherence in burn survivors. Purpose: We tested the hypothesis that whole-body skin wetting would attenuate the rise in core temperature and heart rate, as well as improve perceptual responses, during exercise in the heat in burn survivors relative to non-burned controls. Methods: Thirty participants (10 non-burned controls, 10 with moderate burn injuries (26 ± 8 % body surface area, BSA, burned), and 10 with large burn injuries (59 ± 15 % BSA burned)) completed two experimental visits involving 1-hour of moderate intensity (~5 W/kg metabolic heat production) cycling in the heat (41°C, 15% humidity) with and without whole-body skin wetting (24°C water). Results: We found that end exercise core temperature and heart rate were reduced with skin wetting ( p =0.005, p < 0.001, respectively), with the large burn group having a mean reduction in core temperature of -0.26˚C; 95% CI: -0.45 to -0.08 and heart rate of -13.8 bpm; 95% CI: -22.1 to -5.5 bpm with skin wetting. Additionally, there was a main effect of skin wetting resulting in improved ratings for thermal sensation ( p < 0.001), thermal comfort ( p < 0.001), and rating of perceived exertion ( p = 0.005). Conclusions: Whole-body skin wetting with cool water attenuates the rise in core temperature and heart rate, while improving exercise and thermal perception during exercise in the heat.