Effect of skin wetting on thermal and cardiovascular responses to exercise heat stress in well-healed burn survivors

A large burn injury can severely compromise body temperature regulation due to permanent impairments of the primary heat-dissipating mechanisms, namely blunted skin blood flow and sweating responses of burn-injured skin. We recently showed that supplementing impaired sweating at grafted sites with body temperature water during exercise blunts the exaggerated increase in core temperature in those with burn injuries covering >40% of their body surface area (BSA). However, this method was not effective at attenuating the rise in core temperature in individuals with moderate burn injuries (e.g., 20-40% BSA burned). Further, those observations are difficult to translate to “real world” situations due to the use of body temperature water and spraying only on the grafted sites. Purpose: We tested the hypothesis that whole body skin wetting (with cool water) would attenuate the rise in core temperature and heart rate during one hour of moderate intensity exercise in the heat in burn survivors and not un-injured controls. Methods: Participants completed two experimental visits that involved 1-hour of moderate intensity (5 METs) cycling in the heat (41°C, 15% humidity) with and without whole body skin wetting (randomized) with tap temperature (~24°C) water. We measured core body temperature, heart rate, blood pressure, and rating of thermal comfort. Results: To date we have collected complete datasets on 15 participants: 3 non-burned controls, 6 with moderate burn injuries (20-40% BSA burn injured), and 6 with high burn injuries (>40% BSA burn injured). The non-burned and moderate burn groups had no difference in Δ core temperature between the control trial (0.76 ± 0.17°C and 1.05 ± 0.38°C respectively) and the skin wetting trial (0.82 ± 0.23°C and 1.01 ± 0.37°C respectively; p =0.98). Conversely, in the high burn group the Δ core temperature was attenuated in the skin wetting trial (0.87 ± 0.28°C) relative to the control trial (1.26 ± 0.46°C; p =0.01). The non-burned and moderate burn groups had no difference in end exercise heart rate between the control trial (129 ± 39 bpm and 159 ± 22 bpm respectively) and the skin wetting trial (130 ± 37 bpm; p =0.99 and 153 ± 15 bpm; p =0.24, respectively). Conversely, the high burn group had a lower heart rate in the skin wetting trial (131 ± 24 bpm) relative to the control trial (147 ± 29 bpm; p=0.001). Conclusion: Whole-body skin wetting with tap temperature water is effective in attenuating the rise in core temperature and heart rate during moderate intensity exercise in the heat but only in individuals with large BSA burn injuries. Supported by NIH 5R01GM068865-16 (CGC) This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.