Random itching all over the upper body

16M embarrassing to ask but, random itching happens all over my body (front ,back and arms not the legs) whenever im in hot environment or while im exercising or in harsh sun, it also happens when im nervous or anxious. It is really annoying and i have to rest for a while in cool environment for it to stop. Edit: as someone said that i have to bath daily, yes i do c'mon i wouldnt be asking if that was the problem