Final answer:
Fourth-degree (full-thickness) burns are the most severe type of burn, affecting the entire thickness of the skin and underlying tissues. They require immediate medical attention and cannot be repaired by the body. Treatment involves excision or amputation of damaged tissue and skin grafting.
Step-by-step explanation:
Fourth-degree (full-thickness) burns are the most severe type of burn. They occur when the entire thickness of the skin, along with underlying muscle and bone, is damaged. These burns are typically caused by intense heat, radiation, electricity, or chemicals. Fourth-degree burns require immediate medical attention and cannot be repaired by the body. Treatment may involve excision or amputation of damaged tissue, followed by skin grafting. It is important to keep burn sites clean and sterile to prevent infection.