Detailed answer

Heat rash and prickly heat are two names used to describe the same condition, which is also known as miliaria. They both occur when sweat glands become blocked and the sweat cannot escape to the surface of the skin. This blockage can be caused by factors such as hot and humid weather, heavy sweating, or occlusive clothing. As a result, the trapped sweat leads to inflammation and the formation of small red bumps or blisters on the skin. These bumps can be itchy, prickly, or have a burning sensation, hence the names heat rash or prickly heat. The rash typically appears in areas where sweat accumulates, such as the neck, armpits, groin, or areas covered by clothing. However, the terms heat rash and prickly heat are essentially interchangeable and describe the same condition caused by sweating and blocked sweat ducts.