Heat rash areas: where it commonly develops

Common sites include the neck, upper chest, back, armpits, waist, groin, and skin folds. It may also affect places covered by helmets, straps, dressings, or close-fitting sportswear. Infants can develop it in the neck folds, underarms, and covered nappy area because their skin is often warm and occluded.

The rash may look like clusters of tiny bumps, a rough patch, or small clear blisters. It can itch or sting. Location helps a clinician interpret [Skin Rash](/symptoms/skin-rash/), but it does not identify the cause by itself.

Cool the skin, change out of damp clothing, and wash gently without scrubbing. Pat folds dry and choose loose, breathable clothes. Reduce rubbing from straps or seams where possible, and take breaks from heat or strenuous activity. Keep bedding and towels clean and dry.

Avoid heavy oils and occlusive creams over active bumps unless a clinician recommends them. If dryness remains later, [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) may be discussed. Do not share topical medicines or use [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) without advice.

Seek medical advice if the rash involves the eyes, mouth, genital skin, or a large area; if it becomes painful, hot, crusted, or pus-filled; or if fever develops. Get urgent help for breathing trouble, facial swelling, faintness, or rapidly worsening symptoms. These features can point away from uncomplicated heat rash.

Which areas should I keep dry, and could the location suggest contact irritation, infection, or another cause of [Skin Redness](/symptoms/skin-redness/)?