The role of the hypothalamus in thermoregulation is to maintain the body's internal temperature by acting as a control center for detecting changes in temperature. It receives input from temperature receptors throughout the body and orchestrates responses to maintain homeostasis. The hypothalamus triggers mechanisms such as sweating, shivering, and adjusting blood flow to the skin to dissipate or conserve heat. This regulation is vital for overall metabolic functioning and ensures that the body operates within a narrow, optimal temperature range.