3rd-degree burns are full-thickness burns and will require debridement of the burned dead tissue and skin grafting to heal. In brief: A 3rd-degree burn. 1st- and 2nd-degree burns are partial-thickness burns and will heal on their own, given good wound care and good nutrition. 3rd-degree burns are full-thickness burns and will require debridement of the burned dead tissue and skin grafting to heal. 1st- and 2nd-degree burns are partial-thickness burns and will heal on their own, given good wound care and good nutrition.