I get a rash every time I get overheated. The rash looks like hundreds of red spots and my skin feels stingy right before the red spots appear. When I cool off, the rash disappears within minutes. Can someone tell me what this is?

It's a simple heat rash.

Heat rash -- also called prickly heat or miliaria -- is a common condition in which areas of the skin itch intensely and often feel prickly, or sting, due to overheating. Heat rash looks like tiny bumps surrounded by a zone of red skin. It usually occurs on clothed parts of the body, such as the back, abdomen, neck, upper chest, groin or armpits and goes away on its own within a few days. In severe forms, however, heat rash can interfere with the body's heat-regulating mechanism and cause fever, heat exhaustionheat exhaustion, and even death.

Heat rash occurs most often in hot, humid conditions, but you may develop it in cool weather if you are overdressed.

Heat rash begins with excessive perspiration, usually in a hot, humid environment. The perspiration damages cells on the surface of the skin, forming a barrier and trapping sweat beneath the skin, where it builds up, causing the characteristic bumps. As the bumps burst and sweat is released, you may feel the prickly, or stinging, sensation that gives this condition its common name.

The best treatment for heat rash is to provide a cooler, less humid environment. Keep the affected area dry. Dusting powder may be used to increase comfort, but avoid using ointments or creams-they keep the skin warm and moist and may make the condition worse.

Treating heat rash is simple and usually does not require medical assistance. Other heat-related problems can be much more severe.