A rash is any redness and itching of the skin. A heat rash is a red or pink rash usually found on body areas covered by clothes. It can develop when sweat ducts (pores) become blocked and swell and often leads to discomfort and itching. Heat rash is most common in babies, older adults and people who are overweight or sick, but can affect anyone. Heat rash looks like dots or tiny pimples and commonly appears on the head, neck and shoulders. Areas with heat rash can get irritated by clothing or scratching and sometimes a secondary skin infection may develop. Seek medical care and treatment if you see signs of heat rash.
Attribution: Straight Talk Foundation