Which organ is primarily responsible for maintaining body temperature?

The skin is primarily responsible for maintaining body temperature due to its role as a barrier and its various physiological functions. It possesses sweat glands that produce sweat, which, when evaporated from the skin's surface, cools the body. Additionally, the skin can regulate temperature through the dilation and constriction of blood vessels. When the body is overheated, blood vessels in the skin dilate to increase blood flow, promoting heat loss. Conversely, in cold conditions, these vessels constrict to retain heat.

While the heart, liver, and lungs have important roles in overall body function and metabolism, they do not directly manage body temperature in the same manner. The heart pumps blood, the liver processes nutrients and toxins, and the lungs facilitate gas exchange, but it is the skin that actively engages in thermoregulation through sweating and blood flow regulation.