Jul 27, · For adults, heat rash usually resolves within a few hours, or in more severe cases, up to a few days or weeks. There are a few possible timelines . Aug 13, · The cause of heat rash is often friction on the surface of the skin. Adults usually develop heat rash on the parts of their bodies that rub together, .
May 14, · Heat rash (prickly heat or miliaria) is a mild inflammation of clogged sweat ducts. When the sweat ducts are blocked, the sweat cannot come to the skin surface to evaporate and becomes trapped under the skin. The rash is characterized by small, raised bumps (like coarse sandpaper) spread evenly across small patches of skin.