Exertional heat illness (EHI) occurs mainly in active individuals pushed to their physical limits, resulting in overheating from generation of heat faster than what the body can dissipate [1]. The resultant dysfunction at cellular and organ level leads to a spectrum of diseases from minor heat cramps through heat exhaustion to life-threatening heatstroke [2]. In mass endurance events, runners with heat illnesses are typically treated with ice packs or cooled with ice water in the prehospital setting [3], before the more definitive methods of cooling by immersion in ice water [4] or body cooling units (BCUs) [5] in the hospitals.