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| Alaska State Library - Historical Collections |
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Hypothermia
There is a reason why all Alaskan Wilderness First Responders assume a patient has hypothermia when first coming on scene: Alaska’s cold & wet environment is perfect for the onset of hypothermia. Hypothermia is a medical emergency that occurs when the body’s temperature drops to a level that inhibits proper function; this can occur when the body’s core temperature is below 98.6 degrees F. Hypothermia can occur quickly, as well as slowly, over the course of a few days. For example, an individual may become hypothermic after multiple days of traveling in rainy, 40 degree weather due to a slow but steady decrease in body temperature.
Signs & Symptoms
The beginning signs of hypothermia are 'the umbles': mumbling, bumbling, stumbling, & fumbling. Slurred speech, shivering, and a lack of fine motor skills, as well as unclear or inconsistent thoughts and conversation. Moderate hypothermia occurs when the body’s temperature drops below 95 degrees. Signs of moderate hypothermia include: dazed consciousness, loss of fine motor coordination - particularly in hands, slurred speech, violent shivering and irrational behavior, like paradoxical undressing, where a person starts to take off clothing, unaware that he/she is actually very cold. Severe hypothermia occurs when the body’s temperature drops below 92 degrees. Signs of severe hypothermia include: shivering in waves – violent, uncontrollable shaking interrupted by calm pauses that increase in duration until shivering finally ceases. Victims might fall to the ground, incapable of walking, and curl up into a fetal position to conserve heat. Muscle contract, skin becomes pale, pupils dilate, & pulse rate decreases. At 90 degrees, the body shuts down all peripheral blood flow and reduces breathing and heart rate, in an attempt to keep the body alive at all costs. At 86 degrees, the body is in a "metabolic icebox," where the person looks dead but is still alive and able to be saved with professional medical care.
Prevention
When traveling in the backcountry, it is essential to know the signs & symptoms of hypothermia. When a person is exhibiting the beginning signs of hypothermia, movement, water, & dry layers should recover the victim. As hypothermia develops, it becomes increasingly difficult to raise the individual's temperature to 98.6 degrees F. A severely hypothermic individual will not survive long without medical attention. The key to fighting hypothermia is prevention – staying dry and hydrated is absolute priority. Never allow your clothing to become wet from sweat, water, or snow. Water conducts heat 25 times faster than air, so staying dry is the most important way to stay warm. Keeping hydrated allows the body to perform properly and stay warm, as well. Dehydration leads to a decrease in body temperature and reduced mental clarity and awareness. Stay hydrated! Adequate layering is also essential, as heat loss can rapidly reduce an individual’s core temperature. Do not wear cotton when recreating outside, because cotton is extremely hydrophilic, meaning it absorbs water, and loses its insulating properties when wet. Use synthetic clothing or merino wool and always bring a shell layer to shed water and snow. Layers also help to manage heat loss and cut down on perspiration, increasing your ability to change your clothing to match your heat output. Large amounts of heat can also be lost through conduction, or the exchange of heat between to objects in contact, like your hand on a cold snow shovel handle. This is why it is essential to always use a sleeping pad when camping and sitting on cold surfaces, and they can even be used to prevent heat loss from your feet when standing.
For more visit... http://www.bt.cdc.gov/disasters/winter/faq.asp
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Frostnip
Frostnip is the freezing of the top most layer of skin and is a very mild version of frostbite. Frostnip is generally easy to reverse, with re-warming of the skin. When frostnip occurs the skin will appear white and sensation may or may not be present. Rewarming can be induced by placing the affected area on another’s warm skin or by merely covering the affected area with a facemask, hat, or glove. Afterwards, the skin may become very dry or blister and will often times be more prone to future cases of frostnip or frostbite. Do not rub frostnip as the ice crystals within the skin can cause damage when moved. Frostnip most commonly occurs on the nose, cheeks, ears, fingers, and toes. If a part of your body feels exceptionally cold on the surface, take preventative action to avoid frostnip by covering the exposed skin or increasing the insulation over the area.
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| Alaska State Library - Historical Collections |
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Frostbite
Frostbite can occur within seconds in extreme cold or windy conditions in one of two stages: superficial frostbite & deep frostbite. Superficial frostbite is the freezing of all the layers of skin, while deep frostbite includes the freezing of muscle and even bone in extreme cases. While it may sound superficial, all cases of frostbite can incur serious consequences, including loss of appendages or even limbs. Superficial frostbite appears white, with no sensation, and the skin feels soft and slushy to the touch. Deep frostbite also appears white, without sensation, but the skin feels hard and waxy to the touch. To rewarm frostbitten areas, soak the affected area in 100 degree water – the water should feel warm, but NOT hot! Do not use water that is too hot, as additional severe damage to the affected area will occur. It is important to note that once a frostbitten area is rewarmed, the numbing sensation is dispelled and intense pain will occur. The victim might even vomit or faint due to the extreme pain of the blood returning into the capillaries. If a person acquires frostbite on their foot in the backcountry, it is important to consider when the appendage should be rewarmed, if it is possible, because once the foot is rewarmed, travel will become impossible. If someone is both hypothermic and frostbitten, increasing the core body temperature should always be a priority over attending to the frostbitten areas. Be particularly careful when using white gas in extreme cold, as white gas freezes at temperatures far below those experienced in even the coldest winter environments. Super-cooled white gas can cause instant frostbite if contact is made with the skin – always use gloves when handling white gas in cold temperatures.
For more visit... http://emergency.cdc.gov/disasters/winter/staysafe/frostbite.asp
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| US NATIONAL ARCHIVES |
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Immersion Foot
Trench foot, also called immersion foot, occurs when the foot is exposed to wet conditions for extended periods of time. Trench foot can occur any time of the year in Alaska, and the large amount of wet environments makes trench foot difficult to combat. Signs of trench foot include: reddening with numbness, tingling pain, and/or itching. In more severe cases, the skin becomes pale and mottled, or even dark purple, grey, or blue, as the effected tissue generally dies and sluffs off. After six hours of trench foot, permanent tissue damage can be present and after twenty-four hours, the appendage may be lost. Once trench foot occurs, the circulatory damage may may be irreversible and the individual may be more prone to trench foot in the future.
Prevention
It is often said that Xtra Tuffs, a neoprene lined rubber boot, are the Alaskan sneaker – and for good reason – as exposure to wet terrain is essentially guaranteed in the Alaska backcountry. However, rubber boots do not let the foot breathe and hold moisture inside the boot. Waterproof hiking boots are often useless, as once water gets into the boot, during a creek crossing for example, it is also held inside, much like a rubber boot. Trail running shoes might be a good choice for some activities, but many are not waterproof at all and also may not provide enough support for traveling over difficult terrain. Choose your footwear to match the conditions and activity.
Fight off trench foot by taking time to allow wet feet to dry and use sleeping socks, which stay in your sleeping bag and are to never leave, used only for sleeping in. As soon as you get into your sleeping bag, put them on and enjoy a night of dry, warm feet. Even if you have to put on yesterday's wet pair of socks the next morning, leave your sleep socks in your sleeping bag and reserved for sleeping. Although, they are a special treat on the last day or back at the car!
For more visit...
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