Raynaud's: The big chill for fingers and toes
Blood vessel spasms can make the cold a painful experience.
In 1862, Maurice Raynaud wrote about 25 patients who developed "pale, cold fingers" in response to cold temperatures. The paleness later gave way to a bluish, then a mottled red color. The young physician believed that a nerve problem was the cause.
We now know that the changes come from a sudden spasm of blood vessels. Cold and stress normally narrow small blood vessels in the skin. This redirects blood flow away from the extremities and toward the internal organs. It's a way to conserve heat and prevent excessive blood loss in case of injury. In people with what is now called Raynaud's phenomenon (or Raynaud's syndrome or disease), the narrowing happens suddenly, completely blocking blood flow to the skin. It is a painful condition that can affect the fingers, toes, lips, ears, knees, nipples, or nose.