As the body cools, what physiological change occurs in the extremities?

When the body begins to cool, a physiological response is triggered to preserve core body temperature and maintain heat. In this context, the blood vessels in the extremities constrict, a process known as vasoconstriction. This response serves to reduce blood flow to the skin and limbs, thereby minimizing heat loss from the body's surface. By constricting the blood vessels, the body works to maintain warmth in vital organs and the core, which is crucial for survival in colder conditions.

The mechanisms involved in this response are controlled by the autonomic nervous system, which detects changes in external temperature and adjusts blood flow accordingly. This adaptation is a critical aspect of thermoregulation, ensuring that while the extremities may experience colder conditions, the body's vital functions remain supported by focusing warmth toward essential areas.