When you start to feel overheated stop exercising. If you are in the middle of a game, drop to the ground to let the referee know that you need to come out of the game. As soon as you get of the field, pour water on your head, get out of the sun, and drink plenty of fluids. You can prevent most heat related problems by drinking plenty of fluids before, during, and after exercise or a game. Hydration Failure to drink adequate fluids leads to dehydration.
Dehydration can lead to fatigue, headaches, and even muscle cramps.
Even if you don't have any of these symptoms, you still need to be sure that you get adequate fluids. This is especially important during the August practices and the early games in the season. Drink more fluids than you think you need. Thirst is not a good indication of needing fluids. Drink fluids before practice or a game.