What should you know about viral heat rash?

Heat rash usually appears where sweat, heat, friction, or tight clothing keep the skin damp. It may cause prickling, small bumps, itching, and mild redness. A viral rash may occur with fever, tiredness, sore throat, cough, or other illness features, and it may spread beyond areas exposed to heat. [Heat Rash](/conditions/heat-rash/) explains the condition; [Skin Rash](/symptoms/skin-rash/) and [Skin Redness](/symptoms/skin-redness/) can help you describe what you see.

Move to a cool environment, loosen clothing, keep affected folds dry, and rinse sweat away with lukewarm water. Pat rather than rub, and avoid heavy fragranced products that can trap heat or irritate broken skin. [Emollient Therapy](/treatments/medical-dermatology/emollient-therapy/) may be discussed when dryness is prominent. Do not apply [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) to a suspected infection or use them on a child without suitable guidance. Avoid scratching, since damaged skin can become infected.

Contact a clinician if the rash is worsening despite cooling, lasts beyond the expected recovery, becomes painful, develops pus, or is accompanied by significant fever. Seek urgent help for breathing difficulty, swelling of the lips or tongue, confusion, fainting, or a rapidly spreading purple or blistering rash. Infants and people who seem unusually sleepy or unwell need prompt assessment.

Ask whether the pattern fits heat rash or a viral eruption, whether any medicine or product could be contributing, and which symptoms require review. Mention fever, recent travel, sick contacts, new products, and whether cooling changes the rash.