Wind chill: The term used to describe the rate of heat loss on the body resulting from the combined effect of low temperature and wind. As winds increase, heat is carried away from the body at a faster rate, driving down both the skin temperature and eventually the internal body temperature. Exposure to low wind chills can be life threatening to both humans and animals alike. Water freezes at 32°F (0°C) regardless of what the wind chill is. See also: Heat index.