Hypothermia is a disorder related to cold temperatures. Humans are considered to be a tropical species. Normal body temperature is 98.6 degrees Fahrenheit (37 degrees Celsius.) For humans to remain in their comfort zone, temperatures would, in a perfect world, never go over 98.6 Fahrenheit. Of course this is not a perfect world and for humans in the Northern Hemisphere, temperatures plummet in winter. The human body is able to compensate for small variations in temperature because of temperature sensors in the skin.

How the Body Responds to Temperature Change

The human body responds to body core temperatures above 98.6 degrees Fahrenheit by perspiring, which removes moisture from the body tissue and sends it to the skin surface. The moisture then evaporates, taking much of the excess heat with it. The reason humans become thirsty in hot weather is because the fluids lost through perspiration need to be replaced to avoid dehydration.

With that said, the human body responds to plummeting temperatures by shivering. This is how the body tried to replenish its heat supply. Shivering is nothing more than the contraction and expansion of muscle occurring on a very large scale. This muscle action is able to produce body heat through friction.

Hypothermia

Hypothermia occurs when our body’s core temperature goes below 95 degrees Fahrenheit (35 degrees Celsius.) This is a sub-normal temperature that makes it impossible for our body to regenerate enough heat to maintain normal bodily functions.

Development

Many different factors contribute to the development of hypothermia. Age, body size, weight, duration of exposure, exhaustion, nutrition, health, wind velocity, wetness, medications, alcohol, caffeine and frigid temperatures all decrease the amount of heat our bodies produce. These things can also increase heat loss and interfere with temperature stability.

Causes of Heat Loss

Radiation

This occurs when heat radiates outward from the body to a cooler environment.

Conduction

Conduction is the loss or transfer of body heat by the contact of our body to a cooler object; the heat leaves the body and is transferred to the object. Example: When our body is lying in snow for a long period of time.

Evaporation

This is when the human body loses heat through the process of removing water from the skin surface.

Convection

Convection is when cool air moves across the skin’s surface and heat is transferred to the cooler air, which cools the body.

Respiration

This is when inspired air is raised to body temperature and exhaled.

Every one of these things cause heat loss from the human body and can play a role, either large or small, in the development of hypothermia. Dependent factors include head cover, the type of clothing worn, wind, temperature and weather conditions.

When the human body develops hypothermia, the deficit of heat is shared by both the body’s core and shell. Though much of the human body is core, the term “core temperature” involves mainly the area of the body’s brain, heart and lungs.

Signs of Hypothermia

Threat

When the body’s core temperature drops to 98 degrees Fahrenheit (36 degrees Celsius,) the threat of hypothermia exists. At this point a person will increase activity in order to keep warm. The skin can become numb, pale and have a waxy appearance. Shivering begins and muscles become tense. Fatigue and signs of weakness become apparent. If the person can become active and stay active, hypothermia can be avoided.

Mild

When a person’s core temperature drops to between 94 and 95 degrees Fahrenheit (35 to 34 degrees Celsius,) mild hypothermia will set in. Intense shivering that can’t be controlled wracks the body. At this point the person is very alert and is still able to help himself. However, body movement can be uncoordinated because the cold is causing some discomfort and pain.

Moderate

Moderate hypothermia occurs when a person’s core temperature drops to between 92 and 89 degrees Fahrenheit (33 to 31 degrees Celsius.) At this point shivering stops, mental confusion and apathy set in and the body’s muscles become stiff. The person is now unable to speak properly. Speech will become slow and vague, breathing will be shallow and slow and drowsiness and peculiar behavior may occur.

Severe

Severe hypothermia sets in when the body’s core temperature drops below 89 degrees Fahrenheit (31 degrees Celsius.) Symptoms are cold, bluish skin, dilated pupils, weakness, lack of coordination, exhaustion, slurred speech and the appearance of intoxication. The victim is most likely to be in denial and be opposed to help from others. Gradually, the victim will drift into unconsciousness. The breathing will be so shallow it can’t be determines, the muscles will become rigid and the victim will appear lifeless.

Treatment of Hypothermia

Introduction

The treatment of hypothermia has been a controversial subject for centuries. Then percent of US casualties in Korea were related to the cold. Remember that hypothermia is often similar to a variety of conditions, including death. Always act on the premise that the victim is alive. Many patients who appeared cold, stiff and in a cyanotic state with fixed pupils have been successfully resuscitated in the emergency room. Prognosis of death should always be withheld until the patient’s body has been brought to normal.

Hypothermia always causes severe reaction within the victim’s body because it will always try to protect itself and retain any heat that remains. The most important reaction is vasoconstriction. When this occurs, blood flow to the body’s extremities stop because the body is trying to conserve heat that is critical to the body’s core.

When the body’s core temperature reaches 87 degrees Fahrenheit (30 degrees Celsius,) its heat production source is shivering. This helps blood circulate to the extremities, which minimizes vascular collapse while the body is being warmed slowly. By inducing vasodilation, patients can experience re-warming shock.

It is important that the body’s core is re-warmed before the extremities to prevent the patient from going into ventricular fibrillation. Gentle handling is imperative and the patient should never be allowed to participate in even the most moderate exercise, as this can cause cold blood to be pumped to the heart.

If the body’s core temperature is below 90 degrees Fahrenheit (32 degree Celsius,) the amount of circulating blood within the body is extremely minimal. Basically speaking, the patient’s body is a metabolic ice-box and warming it too quickly can be dangerous to the cardiovascular system.

Threat

If the threat of hypothermia exists, a shelter should be built out of any materials on hand to get the person out of a cold, windy or wet environment. Next, build a campfire or light a portable stove to provide warmth to the body. Give the person a hot drink. Never give alcohol, tea, coffee or any liquids containing caffeine. Wrap the victim in a blanket, or help him add layers of clothing to keep remaining body heat in. Be sure he’s wearing a hat, or cover his head with a blanket, jacket, towel or other item. Once these things have been done the person will recover quickly.

Mild

Move the person out of the cold as quickly as possible, being sure that his head and neck are covered. This helps the body’s core temperature to rise and prevents further heat loss.

Give the victim a warm, sweet drink, but never administer alcohol or drinks containing caffeine. Have the person eat a high energy food. Allow very limited exercise to help generate body heat, but use caution. Exercise also decreases energy.

Moderate

Remove the victim from the cold, being sure his neck and head are covered to retain body heat. Apply lukewarm heat to the armpits, chest, head, neck and groin, using moist towels, hot water bottles or a Thermo pad. Offer warm liquids that have been sweetened, but give no alcohol, tea, coffee or other drinks containing caffeine. Take the victim to the nearest emergency room so he can be checked by a health care professional.

Severe

Warm a sleeping bag and put the victim into it with one or two other people, being certain there is skin to skin contact in the area of the upper torso. Have the people who are laying beside him exhale warm air near the victim’s mouth and nose. Keep the victim awake and ignore his requests or demands to be left alone. This patient is in real trouble, but most likely he will be in denial. Keep a close eye on him, continuously. Apply lukewarm heat to stop core body temperature from decreasing further.

If the victim is unconscious, handle him gently. At this point the heart is very sensitive. Always assume the patient will recover and do not give up attempts to keep body core temperature from dropping further. Constantly monitor the victim’s pulse at the carotoid artery (neck.) If no pulse is found after two minutes, check the other side of the neck for the same duration of time. If the victim is breathing or has a pulse, do not give CPR, even if vital signs are extremely faint. Keep a close eye on the victim for any change in vital signs.

If there is no pulse found after checking both sides of the neck for a two minute duration, start CPR immediately. Stop only when the heart begins beating or when the person giving the CPR is in danger of exhaustion.

Get the victim to the hospital emergency room immediately. Medical assistance is imperative to prevent death.

Caution

Treatment of hypothermia needs to be approached using extreme caution. It is very easy to cause additional harm if you use the wrong method of treatment. If the level of hypothermia can’t be determined visually through signs and symptoms, it should be assumed that severe hypothermia is present.

Research has concluded that the most effective and safest method of hypothermia treatment is to re-warm the victim through inhalation. The problem is that most times the equipment for this procedure is not available except in hospitals.

Remember

• Handle the victim gently and give him no alcohol or caffeine.

• Never re-warm the victim quickly. This will only cause further complications and possibly even death.

• Seek or create shelter from cold, rain, snow and wind.

• If no other shelter is available, head for a wooded area where you can find materials to create a shelter or build a fire.

• Build a windbreak out of blocks of snow, rocks, tree limbs, branches, slabs of bark, or evergreen boughs. If none of these are available, dig a trench in the snow or make a snow cave.

• Find natural shelter behind a dense group of trees, at the foot of a slope, on the windless side of a ridge, under fallen logs, or behind a cropping of rocks.

• Conserve your body heat by huddling in a blanket or adding layers of clothing. If there are other members of your party, you should all group together to provide each other with maximum body warmth.

• Replace damp clothing that is next to the skin.

• Loosen your boot laces. This increases circulation. Place feet, boots and all, into your backpack.

• Place evergreen boughs on the ground to insulate your body from the cold.

• Put your hands under your armpits or between your legs.

• If there is another person with you, lay spoon fashion or back to back to provide each other with the maximum body heat possible.

• Rub the hands and feet of your companions briskly to create friction. Have them do the same for you. Friction helps circulation and creates body heat.

• Snack on small bites of high energy foods, such as candy, nuts or energy bars.

• Ignite both ends of a fuel stick. This will give you and your companions four hours of heat.

• Exercise to keep the body’s circulation system working before hypothermia has a chance to start.

• Search for dead branches, dry twigs and bark to build a fire. Some good fire supplies can often be found in old fallen logs.

• Stay in a sheltered area out of the wind. Never let anyone leave the campsite alone for any reason.

Building a Fire

• Build a fire base using large pieces of wood.

• Pour fire starter on the base.

• Lay evergreen boughs over the base to hold kindling.

• Light the fire starter and gently blow on it to ignite the kindling.

• Add medium sized wood pieces and then larger logs or lengths of larger branches to keep the fire going.

Prevention of Heat Loss

Always remember that the human body loses heat through conduction, convection, evaporation, radiation and respiration. Here are some tips to help you retain body heat.

• Cover your nose and mouth with loosely knit fabric such as woolen mittens.

• Wear layers of clothing that breathe.

• Put an insulating cover between your body and the ground. Evergreen boughs work great.

• Always keep your hands, head and feet covered.

• Protect your body from wind by retreating to a sheltered area.

Get Help

• Send for help. If possible send two members of your party. Be sure they mark the path and note landmarks when they are traveling out of the area. They should also keep track of the distance and time.

• When those people reach a telephone, they should notify a park ranger or the local sheriff. These people will then call the appropriate rescue team.

• Be sure to give the park ranger or sheriff the number of the phone where the call is made. Arrange for rescue workers to meet the people who called for help.

Hopefully you will never experience a need for this information, but make a copy of it and place it in your first aid kit. Be sure to take along safety equipment that will help you survive if the worst happens. Be prepared.

Emergency Equipment List

• Two or three fire starting kits, matches and one or two lighters. You can never have too many ways of making fire.

• A space blanket. This can be used as a heat reflector, wind break, or for signaling a helicopter or plane.

• Pocket knife.

• Fuel stick.

• Wire saw. This can be used for cutting evergreen boughs or firewood.

• Plastic garbage bags. You can wrap yourself in these in inclement weather.

• Ensolite pad to use as an insulator between you and the ground.

• Low temperature electrical tape. This can be used to repair boots, clothing, sleeping bags, tents and a wide variety of other items.

• A head lamp with at least three extra bulbs and sets of batteries. This allows you to have both hands free should an emergency happen at night.

• A compass, flagging tape and a map. Remember to remove the flagging tape when you leave the area.

• Extra layers of clothing.

• A whistle and a mirror, plus 100 feet of heavy cord.

• Plenty of bottled water.

• Extra food, including that which is high in energy.

• A metal cup or pot for melting snow.

• Water purifying tablets.

• Sunscreen and sunglasses.

• Bathroom tissue.

• A snow shovel.

First Aid Kit List

A first aid kit is very important to take along on any outing where you will be a long way from medical help. The following items will help you cope with any emergency.

• Triangular bandages to hold splints and compresses in place.

• Sterile pads to dress large wounds.

• Large bandage compresses for large wounds.

• Ace Bandage to hold splints and compresses in place. These will also strengthen injured joints.

• Stretch bandage for muscle and knee injuries.

• Band-aids for small cuts and wounds.

• Anti-bacterial soap to cleanse cuts and injuries.

• Moleskin tape squares for blisters.

• Chapstick for chapped lips, also known as lip balm.

• Sunscreen

• Aspirin or other pain reliever.

• Small scissors for cutting bandages as well as other functions.

• Safety pins for slings or to hold compresses and bandages in place.

• A medical pamphlet.

• Tweezers to remove slivers.

Conclusion

If you follow the advice in this article, you will be prepared for all types of weather and you will also know how to keep hypothermia at bay. If it does happen to set in unexpectedly, you will have instructions and know exactly how to react. With your emergency equipment and first aid kit along, you are prepared for any emergency.

Be sure to let several people know where you are going, the route you are taking and when you will return. Give instructions on what they should do if you are not back within so many hours of your expected arrival. Be prepared.