Heat rash is a skin rash that usually occurs on the back, neck, or chest. The rash looks like tiny, pink bumps. Occasionally, some are pinpoint-size water blisters. The rash can be itchy or feel prickly. Heat rash is sometimes called "prickly heat."
Heat rash is caused by blocked-off sweat glands. Lots of children get it during hot, humid weather when sweat glands are overworked. Infants can also get it in the wintertime with fever or overdressing. Heat rashes are also caused by oils applied to the hair to make it shiny or ointments applied to the chest for coughs. This mainly occurs in infants because the openings of their sweat glands are tiny and can easily become blocked off by ointments or oils. Older children can get heat rashes with exercise.
With treatment, heat rash usually clears up completely in 2 to 3 days.
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