In only the last 10 days, my 8yr old son gets a weird looking itchy heat rash that appears when he overheats. It can appear on any part of his body from his face, back, chest, arms, buttocks ... anywhere. To look at (for which I have some very clear photos taken) it looks like small scars or like whip lashes. I am suspecting that he caught something when he was in a wood with his friend. The strange thing it disappears as quickly as it appears in relation to his temperature. He has been to his GP who has prescribed some creams which appear to have had no effect. I have also taken him to A&E (when I first saw this as it frightened me) and was told he has some allergy and needs to have an allergy test. Does anyone know what this might be or has seen this before?