Skin is not the same thickness over all parts of the body. It is thinnest on the eyelids and thickest on the bottoms of the feet and palms of the hands. Overall the skin averages about a tenth of an inch thick. It becomes somewhat thinner as a person ages, which is why blood vessels become more obvious in older people. Role Probably the most obvious job of the skin is to protect internal organs from physical injury, but it also shields them from infection and exposure to ultraviolet radiation.
Skin insulates the body against heat and cold and helps regulate body temperature as well.
Sweat also carries out to the skin surface waste products that sweat glands have absorbed from the blood . In cold weather blood vessels in the skin contract to conserve body heat. Meanwhile skin also lets us feel the heat or cold, as well as other sensations. Skin forms an important part of the immune system, even beyond its role as a barrier between the body and the outside world. Its immune functions include production of oil and sweat, both of which kill or retard many bacteria and funguses.