Burn injuries, which are normally classified by degree, are often painful and can require extensive medical and surgical treatment. Burns of all three types are also classified according to the thickness and extent of the injury, and can be caused by direct heat from fire or a hot object. A first-degree burn only affects the outer skin, generally requires little or no medical treatment, and can be very painful. Sunburn is a typical first-degree burn. A second-degree burn is deeper and can result in tissue damage and blisters. A serious second-degree burn generally requires medical treatment and can lead to permanent scarring, sometimes requiring post-treatment reparative surgery. Third-degree burns are much deeper and are often initially not as painful, since the nerves are frequently damaged. These burns always require medical treatment and often have to be treated with skin grafts. Injuries caused by hot liquids are generally referred to as scalds, and burns can also be caused by chemicals, explosions, electricity, or friction. Burn injuries are often painful and can require extensive medical and surgical treatment. If you've received a burn or scalding injury caused by a product or by the carelessness of another person, you may have a case to file for compensation, including actual medical costs, loss of income, and pain and suffering.