The body's reaction to heat, radiation, electricity or chemicals which causes damage to the skin and sometimes organs. Electrical and radiation burns may involve tissues underneath the skin, such as the intestinal tract, nerves, spinal cord, heart and brain. Burns caused by contact involve primarily the skin. They can be superficial or destroy all layers of the skin. Any burn that causes singed nasal hairs or the coughing up of darkish sputum requires immediate medical treatment since the respiratory tract may be injured. Burns involving larger areas of the body can result in a great deal of fluid being lost and result in life threatening dehydration. Potential injury is greatest with infants, young children and the elderly.