Hi, I sometimes get a rash all over my body. It only happens when I do sport and sweat, but it does not happen every time. It starts with small red dots that develop into big areas of hardening leather-like skin. My ears swell very big. If I dont sit down, I faint, as my skin is extremely hot. After 2 hours I get very cold , tired and hungry. The skin goes back to normal after ca. 5 hours. Do you have any clue what this could be?