Dip a washcloth in cool water, wring it out and let it sit on your skin for five to ten minutes. If heat rash is accompanied by nausea, dryness, thirst, headache and pallor, move into an air-conditioned setting, drink fluids and seek medical help as soon as possible. Simple heat rash should clear up in a week or less. If not, you may have some other kind of problem, such as eczema. Your rash continues for more than a week or two.
Ice is nice.
When skin is angry, there's nothing like ice to reduce swelling, says Dr. Harkaway. Throw some ice cubes in a sealed plastic bag, wrap in a kitchen towel and apply for five minutes at a time. Smooth on mentholated cream. Follow the directions on the package. Dust with talcum powder after bathing.