Whenever my body temperature rises, whether it be due to exercise or hot environments, I get a severe itch that covers my whole entire back and chest. It feels like thousands of tiny needs pricking me or small electric shocks. I have to cool my skin down otherwise the severe itching sensation remains. There is no rash present when this occurs. I m 17 years old, 150 lbs, and in very good shape. Is there any disease or skin condition that describes these symptoms?