Sweat pore. Coloured scanning electron micrograph (SEM) of a sweat gland pore (centre) opening onto the surface of human skin. This pore brings sweat from a sweat gland to the skin surface. The sweat evaporates, removing heat and playing a vital role in cooling the body and preventing it from overheating. Sweat pores vary in shape and size over the body. Magnification: x315 when printed 10cm high.