text: why is it when you go into an 80 degree bath it's cold but when it is 80 degrees outside you are warm?   it mainly has to do with how fast your body gets rid of heat to the surrounding medium. water can whisk heat away from your body nearly four times faster than air, so it feels cooler to your body. also, a factor with air is going to be humidity. the more humidity in the air, the less sweat evaporating from you skin and thus the hotter (and stickier) it feels.