The human skin is an organ that forms a protective barrier against germs (and other organisms), dirt and liquids and keeps the inside of your body inside your body, and keeps what’s outside of your body outside. Skin also helps maintain a constant body temperature. Human skin is only about 0.07 inches (2 mm) thick. It is extremely important that the skin stays in optimal condition. Two major causes are responsible for the majority of skin irritation and skin lesions: aging skin and excess of friction.