In most cases, heat rash will clear up on its own in a few days if the affected area is kept cool and dry. So cool your body in an air-conditioned room or with a fan, or take a cool shower or bath and let your skin air dry. Once the skin is cool and dry again, don't use any type of oil-based product, which might block your sweat glands.
If your prickly heat does not go away within a few days, or if you develop an infection where the bumps have burst, you may need medication, so call your doctor. Also call the doctor if you have a fever or any other signs of illness. If you have been taking an antibiotic or other new medicine and develop a rash, you also need to call your doctor.
To help prevent heat rash, avoid situations that can lead to excessive sweating, such as hot, humid environments. Avoid strenuous exercise when it is very warm. In hot weather, use air conditioning, fans, and cool showers and baths to stay cool; dry your skin thoroughly; and wear lightweight, loose-fitting clothes. Drink plenty of fluids to cool the body and to keep hydrated.