Growing up in Southern California, I didn't have much experience with cold weather. If the temperature dropped below 50 degrees, we would really bundle up - meaning we'd wear two sweatshirts over our T-shirts. In junior high, we'd complain to our P.E. coaches about having to do calisthenics outdoors, reminding them, "hypothermia is a killer!" Even the toughest surfer guys would wear long pants in January.
I was on my high school swim team, and in the off season I swam with a master's swim club. In the summer, we'd sometimes do ocean swims around the buoy off a breakwater at Venice Beach. If you have ever watched "Baywatch" (it's OK, you can admit it, we've all watched it) you know the one, right at the base of the lifeguard headquarters.
On New Year's Day at noon, the hardiest of us would do the Venice Beach Penguin Swim. We'd race into the water and swim a few hundred yards in the 55 degree water, then shiver for the next few hours. In the interest of full disclosure, I must admit I did this only once and vowed to never do it again.
So, I was very impressed to learn there was a polar bear swim in Wallowa Lake on New Years Day, and that people I know actually participated and lived to tell about it.
However, what I knew in junior high is still true. Hypothermia is a killer. In water at 32 degrees Fahrenheit, most people would lose consciousness within 15 minutes, and could not survive longer than 45 minutes.
This is why it is so important to stay dry when the air temperature drops below freezing. Water draws heat from your body many times faster than air does, which is why people can die of hypothermia in water as warm as 70 degrees if they are immersed for many hours. Likewise, wearing wet clothing in cold weather is a bad idea. It's better to wear fewer dry clothes than more wet clothes.
Humans, like all mammals, are warm-blooded. This means our body functions best in a very narrow range of temperature. Normal human body temperature is 97 to 99 degrees. Hyperthermia is another name for a fever, meaning any temperature above 100 degrees. Hypothermia means low body temperature.
How a person reacts to cold temperatures depends on many factors. Age is one - older people are more vulnerable to hypothermia than the young. Alcohol consumption and drug use in cold weather impair judgment and may contribute to hypothermia.
As your core body temperature drops to near 95 degrees, you will shiver uncontrollably, feel pain or numbness in your fingers and toes, lose manual dexterity and your speech will become slurred. Infants will have bright red, cold skin and will be lethargic.
As your core temperature drops toward 90 degrees, you'll become increasingly confused. You might be combative if others try to help you, and may insist that you are OK. Instead of shivering more as your temperature drops, your body reacts by shutting down blood flow to your arms and legs. Your muscles become rigid.
Below 90 degrees, you'll most likely be unconscious. If semi-conscious, you'll act as if you're intoxicated. Your heart will beat slowly and irregularly.
As core body temperature gets near 80 degrees, your heart rate and respiratory rate will drop significantly. Your skin will be blue-gray, and your pupils may not respond to light.
When core temperature goes below 80 degrees, a human cannot survive.
If you are with someone who is showing any signs of hypothermia, move the person into a warm, sheltered place if at all possible. Remove any wet clothing, then do whatever you can to warm them. An electric blanket wrapped around the torso and head, or hot water bottles under the armpits and on the person's groin are ideal. If these are not available, skin-to-skin contact is another good option.
As long as the person is conscious and not confused, it's helpful to them give warm, non-alcoholic beverages.
If a person gets confused or loses consciousness due to hypothermia, they require emergency medical care. Hypothermia victims should be handled gently when being moved.
In cases of severe hypothermia, a victim may appear to be dead, with an undetectable pulse - but, it is possible to successfully resuscitate hypothermia victims with CPR and slow warming of their core temperature. When in doubt, hypothermia experts recommend doing CPR until medical assistance arrives or until the person responds. People have been known to recover after long periods of severe hypothermia. As the maxim goes, "you're not dead until you're warm and dead."
So, this winter, stay warm, stay dry and stay alive.
Kathryn B. Brown worked as a registered nurse and a nurse practitioner before going to work for the East Oregonian, the Chinook Observer's sister newspaper in Pendleton. She can be reached at email@example.com.