Since hyperthermia happens because your body can't get rid of excess heat, getting into a cooler area is an important element of treatment. If you're outdoors, you should find a shady spot or, preferably, an air-conditioned area to rest in. Reduce your activity so that you don't generate more heat. Drinking a cool, non-alcoholic and caffeine-free drink is also a good idea. If you've been sweating a lot, you may also want to make sure your beverage has some sodium in it to help replenish your salt levels.
If you're overdressed, you should remove articles of clothing to help you cool down. You can also take a cool shower or bath or use a cold, damp washcloth to help cool your skin. If you're suffering severe hyperthermia and experience elevated blood pressure or heart problems, you should seek medical assistance immediately.
The best way to treat hyperthermia is to avoid it. Try not to spend too much time in hot, humid environments -- humidity will slow down or prevent your sweat from evaporating off your skin and cooling you down. Make sure to drink plenty of liquids -- not just water, which can dilute the electrolytes in your body, but other beverages as well. Fruit juices and sports drinks with sodium in them can help.
Wear light, loose-fitting clothing if you're going to be in a warm environment. Take plenty of rest breaks to avoid building up too high a temperature. Pay attention to how you feel -- if something is wrong, you should be able to tell. Don't ignore the signs. Take time to recover and you'll avoid problems like heat exhaustion or heat stroke.
Believe it or not, overheating isn't always a bad thing. There are situations in which a doctor would recommend a controlled application of hyperthermia. In the next section, we'll look at how doctors use hyperthermia in cancer treatments.