What is Hypothermia? It is a decrease in the core body temperature to a level at which normal muscular and cerebral functions are impaired.
Signs and Symptoms of Hypothermia
Watch for the "Umbles" - stumbles, mumbles, fumbles, and grumbles which show changes in motor coordination and levels of consciousness.
Types of Hypothermia
- Shivering - not under voluntary control
- Can't do complex motor functions (i.e. paddling) can still walk & talk
- Slurred speech
- Violent shivering
- Dazed consciousness
- "I don't care” attitude
- Loss of fine motor coordination - particularly in hands - can't zip up jacket
- Irrational behavior - paradoxical undressing - person starts to take off clothing
- Shivering occurs in waves, violent then pause, pauses get longer then shivering stops
- Person falls to the ground, can't walk, curls up into a fetal position to conserve heat
- Muscle rigidity develops
- Skin is pale, pupils dilate, pulse rate decreases
Death from Hypothermia
- Breathing becomes erratic and very shallow
- Cardiac arrhythmias (irregular heartbeat) develops
Assessing If Someone Is Hypothermic
- If shivering can be stopped voluntarily = mild hypothermia
- Ask the person a question that requires higher reasoning in the brain (count backwards from 100 by 9s). If the person is hypothermic, they won't be able to do it.
- If shivering cannot be stopped voluntarily = moderate - severe hypothermia
- If you can't get a radial pulse at the wrist it indicates a core temp
The basic principles of rewarming a hypothermic victim are to conserve the heat they have and replace the body fuel they are burning up to generate that heat.
Reduce Heat Loss
- Additional layers of clothing
- Dry clothing
- Increase physical activity
- Shelter from the environment (i.e. off of cold surfaces out of the elements)
Add Fuel & Fluids
- Carbohydrates - 5 calories/gram - quickly released into blood stream for sudden brief heat surge
- Hot liquids - calories plus heat source
- Fire or other external heat source
Reduce Heat Loss
- Hypothermia Wrap: The idea is to provide a shell of total insulation for the patient. No matter how cold, patients can still internally rewarm themselves much more efficiently than any external rewarming. Make sure the patient is dry, and protected from any moisture in the environment. Use multiple sleeping bags, wool blankets, wool clothing, sleeping pads to create a minimum of 4" of insulation all the way around the patient, especially between the patient and the ground. Include a mylar "space" blanket to help prevent radiant heat loss, and wrap the entire ensemble in a tarp to protect from wind and water. If someone is truly hypothermic, don't put him/her naked in a sleeping bag with another person.
Add Fuel & Fluids
- Warm Sugar Water: For people in severe hypothermia, the stomach has shut down and will not digest solid food but can absorb water and sugars. Give a dilute mixture of warm water with sugar every 15 minutes. Diluted Jell-O works best since it is part sugar and part protein. This will be absorbed directly into the blood stream providing the necessary calories to allow the person to rewarm themselves.
- Apply chemical heat packs or hot water bottle to transfer heat to major arteries - at the neck, the armpits, and at the palms of the hands.
- For a severely hypothermic person, rescue breathing can increase oxygen and provide internal heat.