Heat rash is common in hot, humid weather and is developed when the body overheats and sweat is trapped near the skin. It is nicknamed "prickly heat" because the skin feels prickly and small red dots may appear on the skin. It can be treated at home with items from your kitchen cupboard or over-the-counter medications.
Get out of the heat and into shade or air conditioning.
Dry the affected area by letting the air get to it.
Cleanse the affected area with a mild, non-deodorant soap or cleanser, such as Cetaphil.
Rinse and pat dry thoroughly with a cotton towel. Be careful not to rub or irritate the skin.
Relieve itching by applying Calamine lotion, hydrocortisone (1 percent) cream (not ointment) or an over-the-counter lotion containing dimethicone, such as Moisturel or Cetaphil Moisturizing Lotion. Follow directions on the product and reapply as needed for 2 to 3 days.
Take a soothing baking soda or oatmeal bath to relieve itching. Dissolve 3 tbsp. of baking soda in bath water, or grind 1 cup of dry oatmeal in a blender and add to bath water. Soak for 15 to 20 minutes. Rinse and dry thoroughly. Learn more about natural treatments for heat rash at MotherNature.com (see Resources below).
Try an over-the-counter antihistamine such as Benadryl to relieve itching in adults.
Wear loose clothing made of natural fibers, such as cotton, or polypropylene, which is designed to promote wicking of sweat away from the skin. Wash clothes in mild detergent.
Stay out of the heat as much as possible for a few days until rash clears up.
Consult a physician if rash worsens, becomes infected or if you develop a fever.
Sprinkle cornstarch on your skin in hot and humid weather to avoid heat rash. Learn how to treat heat rash in babies at WebMD (see Resources below). Learn about treating heat rash in children at the University of Michigan Health System website (see Resources below).
Don't use ointments or oils on heat rash that will block pores and trap moisture. Don't irritate or dry out your skin with harsh soaps. Avoid wearing nylon or polyester in hot, humid weather or when exercising.