When running in cold weather, one must consider the combination of wind and temperature. This is known as the effective temperature or wind chill index, which is the combined effect of temperature and air movements on the body surface. The wind makes a tremendous difference in comfort and at what temperature the exposed human flesh will begin to freeze.
There is real danger with frostbite of the feet when running shoes get wet. Sixty-five percent of your body weight is made up of fluids, which are found in and around your cells, and circulate through your body as blood and lymph.