Hypothermia Explained
Hypothermia is defined as "a decrease in the core body temperature to a level at which normal cerebral and muscular functions are impaired." There are several degrees of hypothermia as well as a host of symptoms that accompany them. Learning how to recognize and treat these symptoms can greatly increase your (and another's) chance of survival should you become stranded in a cold environment.
The most general symptom to look for is a case of the "–Umbles." That is, if the person in question has been out in the cold and you notice stumbles, fumbles, mumbles, and grumbles you may suggest that they go inside and warm up. These seemingly small symptoms are a sign that there is a change in motor functions and level of consciousness. These symptoms are present in the mild to moderate degrees of hypothermia.
Degrees of Hypothermia
Mild Hypothermia
A person with a case of mild hypothermia has a core temperature of 98.6° – 96° F. You will notice some shivering (which should be able to be controlled voluntarily). A person with a case of mild hypothermia will not be able to compete complex motor functions but should be able to walk and talk.
Moderate Hypothermia
A person with moderate hypothermia will have a core temperature of 95° – 93° F. The person will seem a bit dazed and will exhibit a loss in fine motor functions, such as being able to zip up their jacket. Also, people with moderate hypothermia may have slurred speech, violent shivers and will display irrational behaviors (removing clothing, unaware of being cold or appears not to care).
Severe Hypothermia
A person with a case of severe hypothermia has a core temperate of 92 ° – 86° and below. Their shivering will come in waves. The pauses between each wave will become longer and longer until all shivering stops completely. Their body is beginning to shut down. A person in this state of hypothermia will not be able to walk and will most certainly fall to the ground. He or she will likely curl into the fetal position in an attempt to conserve body heat. From this point lots of scary symptoms appear. Muscles will become rigid, the skin will be pale, pupils will dilate, and the victim's pulse rate will decrease.
At a core temperature of 90° the body tries to move into hibernation; shutting down all peripheral blood flow and reducing breathing and heart rate. At a core temperature of 86° the body is in a state of "metabolic icebox." the victim will appear to be dead but in fact may still be alive. Their heart rate can be as low as 2–3 beats per minute. Breathing rate may be reduced as much 1 breath every 30 seconds.