Hypothermia is something we rarely think about in California. After all, most of us are “freezing” when the temperature is around 60 degrees. However, I’ve seen the results of hypothermia on climbing trips, and in the mountains in winter, even in California.

If ever you leave the comfort of your couch and space heater, it’s a good idea to know what hypothermia is, how to prepare for cold weather, and what you need to do to prevent it.

Your body is an amazing machine. When the temperatures drop, your body adapts and uses your energy more wisely to keep warm. First, some of your muscle contractions are reduced, and your body spends carbohydrates differently. When the temperature drops even lower, your nervous system slows down, as well. Your body begins using more carbohydrates and produces lactic acid. As a result, your body slows down, and more heat is retained.

Cold causes your blood vessels to constrict. Blood flow is reduced to the skin, fingers, hands and feet. This is why you feel extreme cold in these areas first. This is a matter of survival. Blood flow to these areas brings heat, and the heat is lost into the environment easily from these same areas. This reaction conserves that heat for the core, keeping the core temperature higher. Unfortunately, this will also increase blood pressure, which can lead to problems if you have heart disease.

Have you ever noticed that you start to shiver in colder temperatures? This is the body’s way to generate heat. The muscles and organs shake, generating heat. Unfortunately this method uses a lot of energy and is not that efficient. When this happens, take additional precautions against hypothermia.

Every winter, people die from prolonged exposure to cold. This can happen in any city across the United States. It doesn’t just happen on the summit of Everest. Seniors are at higher risk because their blood flow may not be as efficient as it once was. Young children may be at greater risk because they might not have the fat reserves to help keep them warm. Others may suffer from hypothermia because they just don’t take the necessary precautions in cold weather conditions.

It is important to know when you need to respond to cold. If it is raining, if you’re sweating under that parka, or if you have somehow gotten wet – perhaps by falling into a stream – you will be highly susceptible to heat loss. Other factors are wind; this can be wind created by weather, or by moving quickly, such as when you are skiing, or biking down a hill. This will increase your hypothermia probability.

If you are tall and thin, you are more susceptible than if you are shorter and stouter. Combat this by wearing layered clothing with under-layers made of wicking material, to pull the sweat away from your body. By using layered clothing you can quickly adjust those layers to respond to changing heat and cold as you move forward.

Fat is an insulation, but I would not suggest getting fat to protect you just in case you get cold as there are too many other dangerous factors to consider here. Instead, consider investing in some various thermal, wicking clothing that will protect your core without the side effects of being fat.

Being fit is the first advantage you will have. Staying hydrated will contribute to limiting hypothermia. Keep your fuel stores (glycogen) at a good level. Keep moving to keep your body warm, eat high carbohydrate foods to keep your energy high, and make sure your electrolytes are not depleted.

Do not drink alcohol. Drinking alcohol causes vasodilation, which leads to heat loss. Do not ingest caffeine as it is a diuretic which causes increased dehydration. Do not use tobacco because it is also a vasoconstrictor and will increase the probability of frostbite.

Things to do: Fuel the body with hot liquids, sugars, GORP; add an external heat source (a fire, a heat packet placed around the core, in gloves/shoes); get into dry clothing; climb into a sleeping bag or a hypothermia rescue wrap (see diagram); and body-to-body contact with a warm person is helpful, as well.

If a person has severe hypothermia, they will not be able to digest solid food. In this case, give the patient warm sugar water every 15 minutes. Jello mixed with lots of water and warmed, will provide a little protein along with the sugar calories to help the patient begin to recover.

I’ve seen death from hypothermia on my first Everest climb. When this occurs, the patient’s breathing will become erratic and shallow. They will be in a semi-conscious state, they will have cardiac arrhythmias, ventricular fibrillation, then the heart will stop, and death will ensue.

Clinical signs of death:

* Cold;

* Blue skin;

* Fixed and dilated pupils;

* No discernable pulse;

* No discernable breathing;

* Comatose and unresponsive to any stimuli;

* Rigid muscles.

Dianne Erskine-Hellrigel is executive director of the Community Hiking Club and president of the Santa Clara River Watershed Conservancy. If you’d like to be part of the solution, join the Community Hiking Club’s Stewardship Committee. Contact Dianne through communityhikingclub.org or at zuliebear@aol.com.