Burns injure the skin layers and can also injure other parts of the body, like muscles, blood vessels, nerves, lungs and eyes. Burns are defined as first, second, third, or 4th degree, depending on how many layers of skin and tissue are affected. The deeper the burn and the larger the burned area, the more serious the burn is. Using First Aid correctly on a burn helps the skin heal and can prevent infection.
Attribution: Straight Talk Foundation