Heat rash, or prickly skin as it is sometimes called, is the result of sweat getting trapped right under the surface of the skin. When this happens, little bumps appear on the skin; and when the bumps burst, the released sweat irritates the surrounding area - hence the prickly sensation. The condition is also characterized by the skin becoming red due to the irritation. Having a heat rash is not a serious thing, although it can be very irritating. It does go away on its own after a few days, but there are home remedies that you can try in order to deal with the discomfort.
Baby powder. The simplest thing you can do is to use baby powder after you take a shower. The powder will absorb any excess moisture that can further aggravate the rash. Make sure the powder is unscented.
Aloe vera. This wonder plant has many uses and alleviating the itch and burning sensation that result from heat rash is one of them. You can use the gel from the plant directly or you can buy aloe lotion from the drugstore (unscented).
Ice. Ice combats heat. If the discomfort is too much for you to handle, grab an ice pack or make your own and hold it against the affected area for five to 10 minutes at a time. Repeat as necessary.
Calamine cream or lotion. Lotions or creams with calamine are readily available in drugstores without the need for a prescription. They have a cooling effect on the skin, which is perfect for heat rash.