Heat rash, also known as “miliaria rubra,” is a form of skin inflammation that occurs as clusters of elevated reddish eruptions or tiny fluid-filled blisters as a result of extreme heat. Heat rashes are an allergic reaction to excessive heat in the body. The chest, back, spine, wrists, and elbows are the most common places where they appear. They are more prevalent in children, including newborns. Heat rashes are normally not serious or painful, and they recover on their own within a period of time. If heat rashes persist and extend to other areas of the body, a dermatologist should be seen right away. Heat rashes will lead to skin cancer in a few rare cases (melanoma).