In cold weather, the human body may lose heat faster than it can produce it. The result is hypothermia, or abnormally low body temperature. Symptoms include sleepiness, confusion and clumsiness. Because it happens gradually and affects thinking, a victim may not realize they need help. That makes it especially dangerous. A body temperature below 95° F is a medical emergency and can lead to death if not treated promptly.
Anyone who spends much time outdoors in cold weather can get hypothermia. One can also get it from being cold and wet, or under cold water for too long. Babies and old people are especially at risk. Babies can get it from sleeping in a cold room.