Final answer:
The severity of burns is determined by depth, area (size), heat source, and location. Fourth-degree burns are the most severe and affect underlying muscle and bone. Nerve endings themselves are damaged in these burns, leading to reduced pain perception. Therefore, the correct answer is Option C.
Step-by-step explanation:
The severity of burns is determined by depth, area (size), heat source, and location. Therefore, the correct answer is (c) heat source. Burn severity can be classified into four degrees: first-degree, second-degree, third-degree, and fourth-degree burns. First-degree burns affect only the epidermis and typically heal on their own within a few days. Second-degree burns go deeper into the dermis, causing blistering and requiring proper cleaning to prevent infection. Third-degree burns extend into the epidermis and dermis, affecting the nerve endings and requiring medical attention. Fourth-degree burns are the most severe and affect underlying muscle and bone. Nerve endings themselves are damaged in these burns, leading to reduced pain perception. Full-thickness burns cannot be repaired by the body alone and require medical intervention.