The skin has 3 layers. 1st degree burns affect only the outer layer of skin. While there may be blistering and a lot of pain, these burns are usually not severe. 2nd degree burns penetrate to the middle layer of the dermis and are severe and will absolutely need medical treatment. 3rd degree burns go all the way to, or through, the last layer of skin. They require hospitalization and often result in skin grafts, if the patient survives.