If you want to help prevent heat illness, first monitor the temperature and humidity and plan outdoor activity accordingly. Second, get acclimated. Gradually work toward exercise in the hotter time of the day and gradually increase the length and intensity of your workouts. Third, drink plenty of fluids. Dehydration is a key factor in heat illness. Help your body sweat and cool down by staying well hydrated with water. Don't wait until you're thirsty to drink. If you plan to exercise intensely or for longer than one hour, consider a sports drink instead of water. Sports drinks can replace the sodium, chloride and potassium you lose through sweating. Eating a meal after activity will also replace electrolytes and other nutrients. Avoid caffeinated and alcoholic drinks because they can actually promote fluid loss. Finally, dress appropriately. Lightweight and loose fitting clothing help sweat evaporate and keep you cooler. Avoid dark colors, which can absorb heat.
(This answer provided for NATA by the Marist College Athletic Training Education Program.)