Heat rash is a skin irritation caused by excessive sweating during hot, humid weather It can develop when the sweat ducts become blocked and swell and often leads to discomfort and itching.
Heat rash looks red or pink
rash usually found on body areas covered by clothing. This usually resolves on its own within a couple of days. On the other hand, Grover's disease, results in small red, bumpy spots on the back, chest, arms or thighs. It also follows sweating or some unexpected heat stress.