Heat exhaustion rash: what to know

Heat rash can appear as small red or flesh-coloured bumps, prickling, or itching where sweat collects, such as the neck, chest, back, groin, or skin folds. Heat exhaustion may occur at the same time, with heavy sweating, weakness, dizziness, nausea, thirst, or headache. The rash itself does not establish the cause: contact irritation, allergy, infection, or another skin condition can resemble it. Heat Exhaustion and Excessive Sweating provide useful related context.

Leave the hot or humid setting, rest in a cool room, and let the skin dry. Wear loose, breathable clothing and use a cool damp cloth or a fan. Avoid heavy creams, oily products, vigorous rubbing, and scratching, which can trap sweat or damage the skin. Drink small sips of water or an oral rehydration solution if you are alert and can swallow. Keep the affected area clean and dry; a clinician can recommend treatment if itching persists.

Get emergency help for confusion, fainting, seizure, trouble breathing, very hot skin, or inability to drink. Arrange prompt medical advice if the rash spreads quickly, becomes painful, develops pus or blisters, or does not improve after leaving the heat. Dizziness, dark urine, persistent vomiting, or severe headache can indicate a broader heat illness or dehydration.

Ask whether the appearance fits heat rash, which skin products are suitable, whether a medicine may increase sweating or heat sensitivity, and how to return safely to exercise or outdoor work.