 Most people with hypohidrotic ectodermal dysplasia have a reduced ability to sweat (hypohidrosis) because they have fewer sweat glands than normal or their sweat glands do not function properly.Sweating is a major way that the body controls its temperature; as sweat evaporates from the skin, it cools the body.An inability to sweat can lead to a dangerously high body temperature (hyperthermia) particularly in hot weather.