I don’t know if this is a universal thing or I’m just odd, but often if I’m getting into a bath that’s just a little too hot (and so requires gradual and careful immersion), I break out in goose pimples. This seems pretty counterintuitive - it’s not due to cold, even on the non-immersed parts, as I am in a hot steamy bathroom.
Is there any reason for this? Is the body trying to insulate itself from the heat by standing hair on end, in the same way that it does with cold? Or is it just some kind of short-cut of the nerve endings caused by too much heat?
I believe that the body tries to cool itself by expanding the surface area of the skin (hence, goose bumps) and sending blood to those areas. At least that’s how I’ve always explained to myself the fact that if the shower water is very hot, my nipples get erect and hard. Uh, I should mention that I am a male. (Please, please, please, do not disabuse me of this notion. I’m not sure I could handle the alternative explanations that some legendary Dopers would like to propose.)
I think that ‘goose pimples’ are caused by the skin erecting one’s hairs, to create an insulating layer. Maybe the heat of your submerged parts make the rest of the body feel relatively cold, causing the reaction.