What physiological response occurs when the body overheats?

When the body overheats, the physiological response known as diaphoresis occurs. Diaphoresis refers to excessive sweating, which is the body's primary method of thermoregulation. When the internal temperature rises due to factors such as high environmental heat, physical exertion, or fever, the hypothalamus in the brain triggers sweat glands to produce sweat. As the sweat evaporates from the skin surface, it cools the body down, helping to maintain a stable internal temperature and prevent heat-related illnesses.

In contrast, other options provided do not directly relate to the body's response to overheating. Chills typically occur when the body is trying to generate heat, often during hypothermia or when someone is ill, rather than during overheating. Cyanosis indicates a lack of oxygen in the blood, leading to a bluish coloration of the skin, which is not a direct response to overheating. Edema refers to swelling caused by fluid accumulation in the tissues and is not specifically a response to elevated body temperature. Thus, diaphoresis is the most accurate answer when considering the body’s reaction to overheating.