Skin is the outer covering of vertebrate animals, is the largest organ of the body and has many different functions. This online resource explores the importance of skin as it protects everything inside your body, helps keep our bodies at just the right temperature and, through nerve endings close to the surface of the skin, allows us to have the sense of touch. It considers how skin can become infected with bacteria, viruses and fungi, and can be irritated by chemicals or other substances it is in contact with