How do skin blood vessels respond to cold weather?

In cold weather, the blood vessels in the skin undergo a process called vasoconstriction, in which they narrow to reduce blood flow to the surface of the body. This physiological response is a crucial mechanism for heat conservation, helping the body maintain a stable internal temperature.123

The French physiologist Claude Bernard was instrumental in explaining this phenomenon. Through his research on the vasomotor nerves, Bernard discovered that these nerves control the constriction and dilation of blood vessels in response to environmental temperature changes. This regulatory activity is a primary example of homeostasis, the process by which an organism maintains a stable internal environment despite fluctuating external conditions.42