Hypothermia

Hypothermia is what happens when your body’s heat generation is slower than its heat loss. Your body core temerature (temperature in your torso) begins to fall, which brings on jarring shivers and then, if untreated, progresses to more serious problems like disorientation, irrationality, and death.

Hypothermia is the biggest killer in the outdoors. It’s known as the killer of the unprepared, and I would say the arrogant, also.

Prevention

As with most aspects of survival, an ounce of prevention is worth a pound of cure. Rules of hypothermia prevention:

• Don’t get cold. This seems too obvious to mention. But lots of people think they’re “tough enough.” It’s amazing what mild temperatures can be dangerous, if you allow yourself to be exposed for too long—or can’t help it.
• Don’t get wet. Use rain gear. Additionally, if you’re working up a sweat, that’s making you wet!
• Eat enough (internal heat) of the right things. Proteins and fats are good in prevention of hypothermia, but that changes if you’re already in trouble— if you’re showing hypothermia symptoms, see “treatment,” below.
• Avoid caffeine, other stimulants, and alcohol. Stimulants constrict the blood vessels unnaturally, and alcohol unnaturally opens them up. Both defeat your body’s natural defenses—its “thermostat.”
• Use shelter. In severe conditions, shelter is more critical than water or food. Get out of the wind and rain, and try to put some insulation between you and the elements.
• External heat. Huddle with others or with your dog. Build a fire. But if you are showing symptoms, see “treatment,” below. Strong external heat can be dangerous if you’re already in trouble.
• Physical exertion will generate heat. If you can exert without sweating or breathing hard (heavy breathing exchanges your internal warm air for the cold air outside), then it may be a good way to get back to warm.

Symptoms

Loosely adapted from Hoods Woods website and
Eric A. Weiss, Wilderness & Travel Medicine

Hypothermia, Symptoms by Core Temperature Range
Body Core Temperature, Degrees Fahrenheit	Symptoms
96-99	Mild hypothermia: That charming “bone cold” feeling; you feel cold to the core. Uncontrollable shivering
91-95	Violent shivering in waves. Poor coordination and stumbling. Don’t take the on-and-off effect of this shivering to mean things are better
86-90	Profound hypothermia: Shivering ceases. Muscles are stiff or rigid. Impaired thinking and judgment. You’re in serious trouble. Probably a goner unless rescued.
81-85	Rigidity continues, slowed pulse rate and respiration. Stupor, Immobility
78-80	Unconsciousness, most reflexes cease, heart beat erratic, possible death
Below 78	Cardiac fibrillation. Edema & hemorrhage in the lungs. White foamy discharge from the lungs. Death

The important things to remember about the symptoms and facts listed above are 1. Prevention; and 2. Immediate action to protect and treat the hypothermic individual.

Some shivering is normal in the cold. But if it starts to be that miserable, jarring shiver, you’re moving into serious danger. If it starts coming in spasms, waiting any longer is really bucking for trouble. Don’t wait any longer, or you may be done.

The next stage makes thinking very difficult: if you stop shivering without getting warmed back up, you’re probably done, barring rescue by someone else.

If you are with someone who is shivering or showing any other signs of “mild” hypothermia (or worse), force the issue now: it’s time to get shelter, get dry, and get warmed up.

If you find yourself rescuing someone who can no longer help himself, you have your work cut out for you.

Treatment

Caveats

Your core temperature and the temperature in your extremities can be quite different. The first caveat of hypothermia treatment is not to fool the body into letting the cold blood from your extremities into your core. That flow could put an end to an already cold-compromised core, dropping the temperature into greater danger.

How do you protect against this? First, don’t drink alcohol. Second, external heat sources should be mild and even. No raging fire. General, mild warmth all around. Try to create the same effect as a warm room would have.

The second caveat is that if you administer food or drink, make it warm (not hot—the point is not to cool the body any further. It takes a lot of warm stuff to heat you back up from inside) and sugary. Simple carbohydrates. Something the body can burn quick and easy. Now is not the time for protein or fats.

The third caveat is not to try to feed an unconscious person. There are ways to do it, but unless you have training this site isn’t willing to delve into, don’t try. It involves inserting a tube into the stomach. But a lot can go wrong with this if you don’t know what you’re doing.

Specific Action

• Recognize it early and treat it ASAP. If the victim is resistant, make an excuse that YOU are too cold, or ... something. Save their ego, if you have to. Just ... make it happen.
• Get to shelter, the quickest way possible. That probably means making it or otherwise improvising. The key is to stop the heat loss.
• Remove wet clothing, and replace with dry, if possible. Cover the head! We lose as much as 60% of our body heat through our head and neck. Again, the point is to stop the heat loss.
• Add heat somehow. A small fire; your warm coat; exercise—preferrably isometrics, since that doesn’t make you huff and puff your body warmth out and the external cold in (BTW, shivering is the body’s automatic attempt to exercise), get creative...
• If the victim is profoundly hypothermic (no longer shivering) or unconscious, immediate action to start warming them up is critical. The best method I’ve heard of is for the two of you to get naked, skin-to-skin, in a good sleeping bag (inside shelter). Not talking about anything kinky here, although if the attraction is there for both of you, it could help...
• For an unconscious victim, you can try artificial resuscitation; your body warmth and warm air in their lungs might just be the ticket.

This is just the beginning

The foregoing is very light coverage of the material. There are a lot of ifs, ands and buts. However, what’s here should be useful in most situations—especially if you remember that prevention and early treatment are the real keys.

For more information, I recommend A Comprehensive Guide to Wilderness & Travel Medicine (Adventure Medical Kits), by Eric A. Weiss. It’s small and fits easily, just about any way you want to carry it. It’s the one I carry.

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