Re: My Sweat Creates Poison Ivy Like Rash
Hmmm. It could be that it's exercise that triggers it, not heat. Or it could be an outdoor thing, I frequently get hives and rashes from outdoor pollens.
Or it could be that having your sweat covered in tight clothing is what irritates your skin. You mentioned that the rash popped up mainly in areas covered tightly by clothing or backpack. I suggest you try exercising in minimal clothing, say, just jogging shorts, or something else very light and breathable.