Prickly heat: Heat rash happens when sweat ducts

Heat rash happens when sweat ducts get blocked, causing itchy red or dark bumps on the skin. To relieve heat rash, take a cool bath and stay in an air-conditioned area. Wear light, loose-fitting clothing to help prevent heat rash in hot weather. Heat rash, also called prickly heat or miliaria, is caused by blocked sweat ducts. Here's how to prevent and treat it. Heat rash or prickly heat is a skin problem caused by blocked sweat ducts. It can be itchy and uncomfortable, but it is not serious and can be treated by keeping cool and dry. Miliaria, also known as sweat/heat rash or prickly heat is a skin condition caused by blocked or inflamed sweat ducts. Heat rash is common especially in hot, humid or tropical climates.