What causes heat exhaustion and heatstroke?
Heat-related illnesses, such as heat exhaustion and heatstroke, occur when your body can’t keep itself cool. As the air temperature rises, your body stays cool when your sweat evaporates. On hot, humid days, the evaporation of sweat is slowed by the increased moisture in the air. When sweating isn’t enough to cool your body, your body temperature rises, and you may become ill.