Frozen Mythbusters: Myth #5 of 13.
There are a variety of myths regarding human response to cold exposure. These myths are explained and debunked by Dr. Murray Hamlet, DMV, Dr. Gordon Giesbrecht, PHD, and Frank Hubbell, DO. After posting the thirteen myths, a complete article from the Wilderness Medicine Newsletter will be loaded for anyone interested in all the chilly little details.
Hypothermia is a disease, the severity of which can be determined by the amount of shivering, and shivering is bad.
Here we have several myths bundled into one. The first myth is that hypothermia is a disease. It is not. The important thing to remember is that the individual suffering from a lower than normal core temperature, hypothermia, has normal physiology for that temperature. As long as we do not mess with their physiology, then, with proper support, they should return to normal core temperature without complications. Quite often the most important skill in managing the hypothermic is benign neglect. This means that you need to thermo-protect them so that they retain more heat than they are losing, and you need to maintain blood sugar to keep them shivering.
One very effective way to rewarm a mildly hypothermic patient (who will be shivering vigorously) is shivering itself. Shivering is contraction and relaxation of the skeletal muscles simply to produce heat. A shivering individual, if properly packaged, should rewarm at a rate of about 2ºF per hour. Shivering, along with mental status and the ability to walk, can help to determine core temperature.
So, shivering is good; it is a normal physiologic reaction to a decreasing core temperature. It is our effort to remain warm or produce the heat necessary to regain normal core temperature. Shivering is good, but there is a trick. To keep shivering, you have to have energy to burn – those darn carbohydrates again.
In a well-fed state, at rest, you have about 24 hours of stored glucose in your liver, called glycogen. If an individual is shivering, these glycogen stores will be consumed faster than at rest. The stores will probably last about 6 – 10 hours. Then as the blood sugar level drops, the shivering mechanism will fail, simply because there are not any more logs to throw on the fire. So, in order to keep the hypothermic victim shivering, you have to maintain their blood sugar. If they are conscious, this can be maintained by feeding them a warm, not hot, sickly sweet liquid (again the “sweet” must be real sugar.)
Busted – Hypothermia is not a disease – it is a condition that is brought on by a lower than normal core temperature, and the physiology is normal for that core temperature. Shivering is good; it is the safest and most efficient way to rewarm. And, once again, carbohydrates are your friend – they are the logs you throw on the fire to keep the fires burning.
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