Assessment of sustainable and accessible water-based cooling interventions during heat events through thermoregulation modeling

Abstract

Extreme heat events pose a major threat to human health, particularly in regions with limited access to active cooling technologies. The escalating impacts of climate change have intensified the frequency, intensity, and duration of heatwaves, highlighting the urgent need for sustainable and accessible mitigation strategies. This study employed a modified JOS-3 thermoregulation model to evaluate the physiological effectiveness of three simple water-based cooling interventions—foot immersion, leg immersion, and dousing. The model incorporates dehydration, updated sensor signals, sweating, and modifications related to water immersion and dousing etc. Simulations were conducted using meteorological data from Indian cities representing hot-dry, warm-humid, and composite climate zones. Key parameters such as cooling method, water temperature, and extent of body surface cooling were varied. Among these cooling interventions, leg immersion with 20 °C water achieved the greatest reduction in core temperatureup to 0.7 °C,and delayed the onset of moderate hyperthermia compared to no cooling intervention. Meanwhile, foot immersion offered moderate relief, although its effectiveness declined under severe heat conditions. Dousing, particularly over larger body surface areas, effectively reduced core temperature. Furthermore, dousing also minimized thermal fluctuations in skin temperature compared to other water-cooling methods. Lower water temperatures in both leg and foot immersion further enhanced conductive heat loss, improving overall cooling performance. Overall, findings demonstrate that simple, passive cooling interventions can substantially alleviate physiological heat strain and serve as practical, sustainable strategies for vulnerable populations during extreme heat exposure. The study offers valuable insights into heat-health adaptation and public resilience planning in a warming climate.