Development And Validation Of A Heat Risk Mitigation Tool For Burn Survivors

Burn survivors have an increased risk for heat related illnesses, and a heightened perceptual strain during exercise (thereby impeding physical activity), both due to impaired body temperature regulation. PURPOSE: To develop and validate a freely deployed online model that burn survivors can use to estimate their heat risk during physical activity. METHODS: Gagge’s two-node thermal physiological model was modified to account for the thermoregulatory consequences of burn injuries, namely a decreased ability to sweat at grafted sites. Model inputs included environmental conditions, physical activity intensity and duration, body size, clothing, and burn injury size. The developed model predicts heat risk categorized as either low to moderate (change in core temperature < 1.7 °C) or high to extreme (change in core temperature ≥ 1.7 °C). To determine the accuracy of the model, we compared the core temperature responses and predicted heat risk from adults aged 19 to 61 years with well healed burn injuries (n = 134) or simulated burn injuries (n = 157). Burn injury sizes ranged from 20 to 80% of body surface area. Trials were conducted in our laboratory across a variety of environmental conditions (25 to 39 °C and 20 to 40 % relative humidity) and exercise intensities (46 to 357 W/m2). RESULTS: With heat risk as a binary outcome, the predictive accuracy of the model was 85% and the area under the curve for the receiver-operator characteristic curve analysis was 0.88. The specificity of the model was 85% and the sensitivity of the model was 79%. CONCLUSION: The developed model (burnactivityriskcalculator.org) predicts heat-risks across a variety of environmental conditions and exercise intensities. This model is best used as a mitigation tool for burn survivors, rather than strict guidance on whether an individual should or should not perform a given activity. We anticipate that this tool will inform individuals of their potential risk (or lack thereof) associated with performing physical activity in the heat while also promoting a physically active lifestyle in burn survivors. Supported by: Supported by NIH R01GM068865 (CGC) and F32HL168826 (ZJM)