Hypothermia is the state of having an abnormally low body temperature. In cold weather, the human body may lose heat faster than it can produce it. Symptoms include sleepiness, confusion and clumsiness. Because the onset of hypothermia is gradual and affects thinking, a victim may not realize that he or she needs help, making the condition especially dangerous. A body temperature below 95 °F is a medical emergency and can lead to death if not treated promptly.
Hypothermia symptoms  include General deterioration in the mental faculties, Lethargy and weakness, disorientation,Distinct changes in the speech pattern,loosing motor and muscle functions. But, at the same time, these symptoms might be mistaken for some other disease like diabetes, alcohol usage, stroke, etc.
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.