By: Alan Halcon and Dude Mclean
What, an article about hypothermia in the spring? Sure why not. It really doesn’t need to be freezing to find yourself in trouble. The big chill can move in on you, or someone with you—recognizing the signs and knowing how to properly treat hypothermia can mean the difference between living and dying.
How You Lose Heat to the Environment
Heat always transfers to cold, and it is important to know the four factors surrounding this phenomenon.
Radiation - loss of heat due to the temperature difference. This occurs as long as the ambient temperature is below our bodies 98.6 degrees Fahrenheit.
An example of radiation is the suns heat; one can feel the warmth radiating from the sun. Another example is the warmth felt from a campfire.
Conduction – is the loss of heat through direct contact between objects
An example of conduction is sitting on a cold rock and feeling your butt get cold. Wet clothes coming in contact with your body is another example of loss through conduction.
Convection – is heat loss due to the movement of air or liquid across your skin. The warmer body temperature is carried away and replaced by the cooler air or liquid. Losing heat via water convection occurs more quickly than air convection. An example of air convection is Wind Chill. An example of liquid convection is taking a cold shower or falling in cold water.
Evaporation - heat loss occurring by converting water to vapor
An example of evaporation is the body’s perspiration being cooled at the skins surface.
Evaporation can be responsible for 20-30 percent of heat loss even in temperate conditions. In addition, a non-active person loses approximately 15 percent of his average daily caloric intake through evaporation.
How Your Body Regulates Core Temperature
Vasoconstriction – is the constriction of blood vessels.
Vasodilatation – is the dilatation of the blood vessels
Sweating - cools body through evaporative cooling
Shivering - generates heat through increase in muscle activity. This is limited because of depletion of muscle glucose and fatigue.
Signs and Symptoms of Hypothermia
Any temperature less than 98.6 degrees is linked to hypothermia
In their book “Hypothermia Frostbite and other Cold Injuries” authors Gordon G. Giesbrecht, Ph.d, and Doctor, James A. Wilkerson, write “A mnemonic useful for remembering the early stages of hypothermia is “umbles.” The mildly hypothermic individual: fumbles, stumbles, tumbles, mumbles, and grumbles. The first three items (fumbles, stumbles, tumbles) reflect impairment of motor function, first fine movements and then gross movements. The last two (mumbles and grumbles) indicates intellectual impairment.”
Normal shivering can begin
Cold sensation and goose bumps
not able to perform complex tasks with hands
shivering can be mild to severe
hands are numb
Shivering is intense
obvious lack of muscle coordination
movements are slow and labored
mild confusion, but may appear alert
violent shivering continues
has difficulty speaking
is sluggish in thinking
amnesia begins to appear
gross muscle movements are sluggish
not able to use hands
stumbling is frequent
has difficult time speaking
depressed and withdrawn.
All shivering stops
exposed skin becomes blue or puffy
muscle coordination is very poor
not able to walk
behavior is incoherent and irrational, but may be able to maintain awareness
in a stupor
a loss of awareness of others
pulse and respiration rate decrease
possible heart fibrillation
heart beat and respiration are erratic
pulse may not be palpable
cardiac and respiratory failure
How to determine if someone is suffering from hypothermia
If shivering can be stopped voluntarily the person is suffering mild hypothermia
Ask a question that requires higher reasoning in the brain; e.g. say the alphabet backwards. If the person is hypothermic, they won't be able to do it.
If shivering cannot be stopped voluntarily the person may be suffering from moderate to severe hypothermia
If the person is unable to walk a 30 foot straight line, the person is hypothermic.
It is extremely critical to properly treat a person who is suffering with moderate to severe hypothermia. Failure to properly treat can result in death
There are a few DO NOT DOs one should stick by when treating a person with hypothermia
* Never give alcohol to the victim. Alcohol is a vasodilator and will increase peripheral heat loss
* Never give caffeine to the victim. Caffeine is a diuretic and causes water loss increasing dehydration
* Never allow a victim to smoke. Tobacco/nicotine is a vasoconstrictor and increases the risk of frostbite.
* Never allow a victim to self-help if they are suffering from moderate to severe hypothermia.
* Never and I mean never massage or rub a persons extremities (hands, arms, legs, feet) to get the blood circulating. Doing so can cause a condition called after-drop* and kill the victim.
Treatment Mild Hypothermia
Add more layers of dry clothing
Increase physical activity
get person out of elements
build fire to warm person
increase caloric intake by eating foods with simple sugars. (breads, candy bars, warm water with honey or sugar, etc.
Moderate to Severe Hypothermia
Get person out of elements
Be very gentle with the victim a hypothermic person’s heart is hyper excitable and can lead to arrhythmia
The victim should lay down in the horizontal position
Do not elevate the victims arms or legs while the person is laying down; After-drop can occur.
Apply warm compresses: under both armpits, the groin, and back of the neck.
Give victim warm water with sugar*
If necessary, use hypothermia wrap*
Make sure person heart rate is not present before administering CPR*
After-drop Is where the core temperature actually decreases during re-warming. After-drop occurs by peripheral vessels in extremities dilating if they are re-warmed by external heat sources, rubbing, or massaging. This causes the very cold blood from the extremities to move back to the core. This further decreases the core temperature, and can lead to death. Moreover, this blood is acetic which can lead to cardiac arrhythmias and even death… Re-warm the core only!
Hypothermia Wrap: Make sure the patient is dry. The person must be protected from any moisture in the environment, including a layer to keep the victim from collecting sweat on the skin. Use multiple sleeping bags, wool blankets, wool clothing. 4" of insulation should be all the way around the patient, especially between the patient and the ground to prevent heat loss due to conduction. Include a Mylar "space" blanket to help prevent radiant heat loss. Wrap the entire thing in plastic to protect from wind and water.
Warm Sugar Water: people with severe hypothermia will not be able to digest solid food; however, they can absorb water and sugars. Giving a diluted mixture of warm water with sugar/Jell-O every 15 minutes will allow the victims metabolism to kick in and generate internal heat.
Urination Urinating will help conserve heat. A full bladder uses body heat to keep urine warm rather than vital organs. Once the person has urinated, body heat will be redirected towards vital organs. You will need to help the person urinate. Open up the Hypothermia Wrap enough to do this and then cover them back up.
CPR a person in severe hypothermia may demonstrate all the clinical signs of death, but they may still be alive and can be revived. During severe hypothermia the heart is hyper excitable and administering CPR can result in fibrillation and death.
Be sure the pulse is completely absent before beginning CPR. Remember, the heart rate may be 2-3/minutes apart and the breathing rate 1/30 seconds. Administering CPR at this point may lead to life-threatening arrhythmias. Check the carotid pulse for a longer time period (up to a minute) to ascertain if there is some slow heartbeat. A hypothermia victim is never dead until warm and dead. If there is no discernible heartbeat begin CPR, and be prepared to continue - persons with hypothermia have been given CPR for up to 3.5 hours and have recovered with no neurological damage.
It’s really up to you!
Basic first-aid is often overlooked by even the most experienced outdoorsmen—Red Cross courses