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In the dead of winter, we’re able to stay inside and turn up the heat to stay comfortable, thanks to the availability of power.  In a power-down situation, however, it will certainly be a challenge to stay warm during the winter months in most areas.  If we aren’t careful, we’ll find ourselves at risk for environmental medical issues such as hypothermia.
Causes of Hypothermia
Hypothermia is a condition in which body core temperature drops below the temperature necessary for normal body function and metabolism.  The normal body core temperature is defined as between 97.5-99.5 degrees Fahrenheit (36.0-37.5 degrees Celsius).   Here are some common temperatures converted from Fahrenheit to Celsius:
Fahrenheit               Celsius
32                                  0
50                                10
68                                20
77                                25
86                                30
87.8                             31
89.6                             32
91.4                             33
93.2                             34
95                                35
96.8                             36
98.6                             37
100.4                           38
102.2                           39
104                              40
105.8                           41
107.6                           42
109.4                           43
Once the body core cools down below 95 degrees Fahrenheit (35 degrees Celsius), the body kicks into action to make heat.  The main mechanism for this is shivering.  Muscles shiver to produce heat, and this will be the first symptom you’re likely to see.  As hypothermia worsens, more symptoms will become apparent if the patient is not warmed.
Aside from shivering, the most noticeable initial symptoms of hypothermia will be decreased mental status.  The person may appear confused, uncoordinated, and lethargic.  As the process worsens, speech may become slurred; the patient will appear apathetic or uninterested in helping themselves or may fall asleep.  This occurs due to the effect of cooling temperatures on the brain; the colder the body gets, the slower the brain works.  Brain function is supposed to cease at about 68 degrees Fahrenheit, although I have read of exceptional cases in which even lower temperatures resulted in full recovery.
The body loses heat in several ways.  Heat radiates out of the body from unprotected surfaces.  Most heat is lost from the head area, due to its large surface area and tendency to be uncovered.  Direct contact with anything cold, especially over a large area of your body, will cause rapid cooling of your body core temperature.  The classic example of this would be falling  into cold water.  In the Titanic sinking of 1912, hundreds of people fell into near-freezing water.  Within 15 minutes, they were probably beyond medical help.
Wind removes body heat by carrying away the thin layer of warm air that exists at the surface of your skin. Wind chill is an important factor in causing heat loss. For example, if the outside temperature is 32 degrees F (0 C) and the wind chill factor is at 5 degrees F, your body loses heat as quickly as if the actual temperature outside was at five degrees F.
As with many other situations, the very young and the elderly are most at risk for hypothermia.  Diabetics and those who suffer from low thyroid levels are also more at risk.  One factor that most people don’t take into account is the use of alcohol.  Alcohol may give you a “warm” feeling, but it actually causes your blood vessels to expand, resulting in more rapid heat loss from the surface of your body.  The body normally reacts to cold by constricting the blood vessels, so expansion would negate the body’s efforts to stay warm.  Alcohol also causes impaired judgment, which might cause those under the influence to choose clothing that would not protect them in cold weather.  This also goes for various “recreational” drugs.
The diagnosis of hypothermia cannot be made with a standard rectal thermometer, which doesn’t register below 94 degrees Fahrenheit (there are specific low temperature thermometers available, but will be scarce in a collapse). However, if you encounter a person in a cold environment who is confused and lethargic, and whose temperature does not register, you should assume the patient is hypothermic until proven otherwise.

How Bad Can Hypothermia Get?
If left untreated, hypothermia leads to complete failure of various organ systems and to death.  People who develop hypothermia due to exposure to cold are also vulnerable to other cold-related injuries, such as frostbite and immersion foot.
Frostbite, or freezing of body tissues, usually occurs in the extremities and sometimes the ears and nose.  Symptoms include a “pins and needles” sensation and numbness. Skin color changes from red to white to blue.  If the color then changes to black, a condition known as “gangrene” has set in.  Gangrene is the death of tissue resulting from loss of circulation.  This usually results in the loss of the body part affected.
Immersion foot (formerly known as Trench Foot) causes damage to nerves and small blood vessels due to prolonged immersion in water.  When seen in areas other than the feet, this condition is referred to as chilblains.  Immersion foot appears similar to frostbite, but might have a more generally swollen appearance.
Immersion foot (formerly known as Trench Foot) causes damage to nerves and small blood vessels due to prolonged immersion in water.  When seen in areas other than the feet, this condition is referred to as chilblains.  Immersion foot appears similar to frostbite, but might have a more generally swollen appearance.
Rapid measures must be taken to reverse the ill effects of hypothermia.  They are:
·         Get the person out of the cold and into a warm, dry location. If you’re unable to move the person out of the cold, shield him or her from the cold and wind as much as possible.
·         Take off wet clothing. If the person is wearing wet clothing, remove them gently.   Cover them with layers of dry blankets, including the head (leave the face clear).   If you are outside, cover the ground to eliminate exposure to the cold surface.
·         Monitor breathing. A person with severe hypothermia may be unconscious.  Verify that the patient is breathing and check for a pulse.  Begin CPR if necessary.
·         Share body heat. To warm the person’s body, remove your clothing and lie next to the person, making skin-to-skin contact. Then cover both of your bodies with blankets.  Some people may cringe at this notion, but it’s important to remember that you are trying to save a life.  Gentle massage or rubbing may be helpful, but vigorous movements may traumatize the patient
·         Give warm oral fluids. If the affected person is alert and able to swallow, provide a warm, nonalcoholic, non-caffeinated beverage to help warm the body.  Remember, alcohol does not warm you up!
·         Use warm, dry compresses. Use a first-aid warm compress (a fluid-filled bag that warms up when squeezed), or a makeshift compress of warm (not hot) water in a plastic bottle. Apply a compress only to the neck, chest wall or groin.  These areas will spread the heat much better than putting warm compresses on the extremities, which sometimes worsens the condition.
·         Don’t apply direct heat. Don’t use hot water, a heating pad or a heating lamp to warm the person. The extreme heat can damage the skin or cause strain on the heart and even lead to cardiac arrest!
Making sensible decisions about clothing will be the best preventative strategy for hypothermia; Keep yourself warm and away from situations that will put you at risk, and you’ll have a warm, toasty winter.
Dr. Bones

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