The Deadly Chill
By Patrick O’Neil, PA
Most of us have heard stories about the hiker that was stranded in the woods and ended up succumbing to hypothermia. Or maybe the homeless person who was living on the streets in a major northern or eastern city that was found dead, also passing away from hypothermia. Yet most people don’t realize that it is a very common injury seen in Emergency Departments across that nation.
Every year, there are over 1,500 reported hypothermia cases, and over 650 of those will pass away. Most medical professionals know this is just the tip of the iceberg. We all realize that this is a very under-reported injury. The vast majority of people that have minor hypothermia symptoms recover and never seek medical attention. This makes sense, as why go to the ER if you are no longer in danger?
These cases occur in all environments: Mountains, valleys, plains, even large cities. It is actually pretty intuitive that if the temperature is cool, there is always a risk for hypothermia. As a young man, I lived in the desert Southwest, at 4,000 feet above sea level. We had a mountain range next to us and people liked to go on day hikes. It was common to be in the 80’s in town, but up on the mountain it would be in the 60’s. People would set out from town wearing shorts and a T-shirt, not realizing the temperature would drop a good 20 degrees, and continue with their hike. If something happened to where they ended up getting stuck on the mountain overnight, with the temperature dropping into the 50s, they might suffer hypothermia. I vividly recall several of these individuals died. It can happen almost anywhere. (Did you know there is a ski resort in Hawaii?)
We do see some patterns in what types of individuals are affected. The elderly and very young are more susceptible, those with mental illnesses, and those with drug or alcohol addictions. People with certain medical conditions, such as diabetes, hypothyroidism, Parkinson’s disease, and trauma patients are all more likely to have difficulties regulating their body core temperature. This inability to regulate their own internal temperature will lead to a much more rapid and profound hypothermia than an otherwise healthy individual. It’s hard to imagine, but these populations can have a mortality rate as high as 40%.
Yet, hypothermia is not limited only to those I just listed. Very healthy individuals can also become hypothermic under the proper circumstances. I can tell you that as a young teenager, I probably had hypothermia several times while camping, hunting, or participating in other outdoor activities. At the time, I just knew I was really, really cold and didn’t give it much thought. I did just about everything wrong in those situations, but was able to work through it, get out of the situation, and change my environment just enough to recover. Not once did I check myself into the Emergency Room, even though in hindsight, I was definitely suffering from most of the symptoms of hypothermia. Pure dumb luck also played heavily into those scenarios.
I can also tell you that during my time as a Soldier, I have had to treat individuals in a field environment that had all the classic signs and symptoms of hypothermia. We had the best gear available, were in excellent physical condition….but in the end….the environment also gets a vote. You can very quickly find yourself in a bad situation if the weather takes a sudden shift; and then it’s time for survival mode and the mission may have to wait.
So, what exactly is hypothermia? Most medical definitions would say it is a body core temperature below 95 degrees Fahrenheit. Now, that’s pretty handy information if you happen to be in a hospital and have a rectal thermometer available to you. But most of us aren’t going to be carrying one of those on our person when we encounter somebody that may be suffering from hypothermia. And I’m not quite sure how they would react to me if I casually asked, “Hey, buddy, can I put this thermometer in your butt so I can see if you have hypothermia?” I’m probably not going to get the response I want.
I prefer to simply use symptoms as my gauge for hypothermia. The Swiss have a very nice classification system, based completely on symptoms. I like that. It keeps it simple.
Shivering – this is without a doubt, one of the first signs you will see and should put you on alert that things are not going in the right direction for you. This is your body to trying to increase its internal temperature through muscular shivering. It means your core temperature is dropping and is not currently being regulated properly.
Skin color changes – initially we will all get the nice rosy cheeks, ears, nose, and hands. Later they may become pale. Not really a good sign, as this means your body is now starting to constrict the capillaries in your extremities to bring more blood into the central core.
Increased pulse rate – your body is releasing epinephrine (adrenalin) which causes the blood vessels to constrict, your heart rate to increase, and your pulse will also feel much stronger than normal when you feel for it.
Increased respirations – With the increased heart rate, your respiratory rate will also increase.
Mild mental confusion
Difficulty with fine motor coordination
Difficulty with Speech
Shivering Stops – the body thermoregulation system is starting to fail. The patient may say they feel warm.
Pulse, Respiration, Blood Pressure – whereas they were elevated in Mild Hypothermia, they are now all decreasing. This is a very bad sign that the body is no longer compensating for the hypothermia.
Progressive Decrease in Level of Consciousness – Stupor is setting in. Bad decisions are being made, conversation may be unintelligible, and the ability to concentrate is absent. They may even exhibit “paradoxical undressing” where they take off their clothes and go running around in the cold.
One thing that cannot be seen is the patient is now more susceptible to a cardiac arrhythmia. This means the electricity is not traveling through the heart in the normal pathway. Most likely this rhythm will be atrial fibrillation, which can progress to full blown cardiac failure.
The Key point here is that if you have a person that is showing signs of an altered mental status, with loss of shivering and decreased pulse and respirations…..that person is in a really bad spot and needs immediate assistance
At this point, the body is shutting down. There is a profound decrease in respirations and pulse to the point that there is a 50% decrease in oxygen consumption
Loss of reflexes and voluntary motion – in other words, he cannot walk, raise his arms, etc.
His heart is getting ready to go into ventricular fibrillation and, soon after, death
The best way to treat hypothermia is to prevent it from ever occurring. If you take anything at all away from this article, this is the single most important thing to remember. Stop it before it happens. Failure to plan properly is the single biggest factor leading to hypothermia. You need to prepare for every possible contingency if you believe you may be going into a cold weather environment. Most of these can be applied whether you are going out into the woods, living on the streets, or if you simply lost power in a major blizzard.
You should be asking yourself:
►What is the weather pattern in the area I will be in? (Temperature, humidity, wind, and precipitation)
►How long will I be exposed to the weather?
►What happens if I end up getting stuck in the environment longer than expected?
►What happens if I get injured in that environment?
►What is my plan to stay warm?
►What is my plan to get out of the environment?
►Do I have a communications plan to get some much needed help?
Always let somebody know where you will be on a daily basis. Let them know what you will be doing, and when you should be returning. That way they can alert the authorities if your commo plan fails, or you don’t show up when you said you would. At the very least, they will have a starting point on where to find your body if you failed miserably at all these tasks.
Do you have proper Shelter, Clothing, Food, and Water to sustain you? Remember, your body will require more calories in a cold weather environment.
Do I have the proper equipment needed on my person, in my car, in my home, in my backpack, etc.?
How the body loses heat
It isn’t just being subject to the cold environment that causes hypothermia. A big part of the hypothermia equation is the heat that is lost from the body. I would say a large percentage of the hypothermia cases that I have seen are due to inadequately keeping the heat within the body. I’ve been pretty darned comfortable in below freezing weather when I was properly prepared. I have also had some absolutely miserable experiences in 45 degree weather when I wasn’t properly prepared. Maintaining your own body heat is absolutely crucial in determining if you are going to be a patient, or the one resuscitating the patient.
Radiated Heat – Most of the heat that is lost is because it was allowed to escape from the unprotected, or uncovered, surfaces of your skin. If it is exposed to the environment, then heat can escape through that site. Make sure you have the proper gear to cover all exposed surfaces of your skin.
Direct Contact (Conductive heat loss) – If something cold is touching your skin, such as very cold ground or water, it will sap the heat from your body. Water is very efficient at transferring heat. You will lose far more heat from your body due to moisture than due to cold air. How many of us have gone to watch a football game and it either started to rain or snow. This is when you find out that water resistant materials are really nice to have, and in some cases, an absolute necessity.
Wind – a wind chill factor will cause your body temperature to decrease by removing the layer of warm air that is normally found at the surface of your skin. This can cause some nice goose-pimples or shivering effects. This is when you find out that it is not only really nice to have a water resistant jacket…..but one that is wind proof also! I will never forget the first time I was issued a GoreTex jacket. I thought Christmas had come early that year.
The COLD Acronym
Always remember the COLD Acronym when outdoors. It doesn’t matter if you live in the city or the country. It applies in every situation and condition. I even use this in Texas when outdoors, and we have fairly mild winters compared to most places. I have also used it when on a frozen mountain side in Korea. Remember these basics and they will go a long way in keeping you comfortable; and not becoming a casualty.
COVER: Have a plan to cover every exposed part of your skin. Most body heat escapes from the head, face and neck areas. This is why I love balaclavas. I can roll it up and use it as a simple cap, or roll it down and it covers everything. I don’t go out in the cold without one. PERIOD. A nice pair of gloves or mittens. Mittens are better for severe cold as the fingers are all together and not in an individual glove finger.
OVEREXERTION: You must avoid sweating, for a couple of reasons. First, sweating creates moisture which leads to more rapid heat loss. Second, sweating burns up a lot of energy. If you find yourself in a bad situation, you may need all the energy you can spare. If you must exert yourself, adjust your clothing to ensure you are not overheating.
LAYERS: Inner layers should be something that wicks away body moisture. Polypropylene works great and is what the military issues. Over that I like Wool or silk. Make sure all layers are loose fitting and lightweight. The idea is to trap pockets of warm air next to the body. You will have to adjust how many layers you are wearing depending on your work load. For the outer layer, you will want something that is water repellant and wind resistant. Many cold weather jackets also come with a variety of fillers. Just look for the temperature rating to make sure it is what you need. Also look for nice things like zippers in the arm pit area and fold over zipper flaps to keep the wind out.
DRY: Have you figured out just how important keeping dry is? It’s a recurring theme throughout this article. When we were forced to do long movements in the winter, one of the first things we did when setting up our temporary patrol base was to get out of our wet clothing. While half pulled security, the other half was getting into dry gear. Then we returned the favor. This is especially true for boots and gloves. Fingers and Toes are extremely vulnerable to frostbite. Keep them dry and warm.
Treatment of Hypothermia
If you identify that you have a hypothermia case on your hands, you really should try to seek medical attention. These individuals can crash fairly quickly. I have seen patients body temperatures continue to drop for a short period of time, even after rewarming efforts had started. Always play it safe. My comfort factor stops when I see they are no longer shivering, their respirations and pulse are dropping, and they are having altered level of consciousness, difficulty speaking, etc. You get the idea. It’s time to get this person to medical care
Get the person out of the environment - Most folks would point and laugh at the homeless, naked guy running down the street in the snow. What they don't realize is this person may be getting dangerously close to severe hypothermia. We need to get him out of the cold and wet. Bring him into a warm building. Give him a blanket, some warm food and drink, and call 911. You may save his life. In the woods, you need to change the environmental situation. You may not have a nice, warm, cozy cabin for the person. That’s OK, you can place them behind a wind break, get them off the cold ground by providing a barrier, try to provide some overhead cover, start a fire, etc.
Be Gentle – Too much vigorous movement may throw this person into cardiac arrest. We don’t do vigorous body rubbing or massage anymore.
Remove wet clothing – As I already said, moisture will sap the heat right out of your body. Remove anything wet and put on dry clothing.
Insulate the person from the ground – You want to place a barrier between the patient and the ground. Use your imagination: limbs, branches, pine needles, leaves, etc. I then like to put down a waterproof barrier, like a poncho or plastic. Then I will put a blanket or sleeping bag on top of that. Two products that work extremely well are the Blizzard Blanket and the Hypothermia Prevention Management Kit. The Blizzard Blanket is compact, whereas the HPMK is fairly bulky, but a much better product.
Cover all exposed skin – I really like balaclavas as they cover the face and top of the head. Gloves and scarves are also necessities.
Layering – start piling layers of blankets, shirts, towels on top of the sleeping bag.
You can place hot water bottles or hand warmers in the axillary and/or groin areas to assist in rewarming.
If the person is alert and coherent, warm beverages will help. Stay away from anything with caffeine or alcohol. Contrary to popular belief, a couple shots of whiskey don’t actually do anything to warm you up.
Watch their respirations – You will want to make sure they are taking a breath every 5-7 seconds. If they are breathing slower than that, you run the risk of hypoventilation. You may want to perform artificial respirations to assist them.
If they have no pulse or respirations – Continue to try and rewarm them. THEY ARE NOT DEAD UNTIL THEY ARE WARM AND DEAD. Patients have survived with body core temps in the 50’s. Don’t give up on them until they have been warmed up and still show no signs of life.
DO NOT EVER immerse the person in a hot bath, use a heating pad, or do anything else to rapidly rewarm the patient. You will dramatically increase the risk of a heart attack.