Extreme heat can be dangerous for all children, especially for infants and young children. Heat illnesses include heat stroke, heat exhaustion, heat fainting, heat edema (swelling of the hands, feet and ankles), heat rash (prickly heat) and heat cramps (muscle cramps). They are mainly caused by over-exposure to heat or over-exertion in the heat, and if not prevented, can lead to long-term health problems and even death.