Cold Injuries and Recognizing Hypothermia

The best treatment for cold injuries is to recognize the early warning signs and take action. Hopefully, with care one avoids the prospect of injury.

It is always a good idea to remain cognizant of possible injuries from the cold. Of course, our hands and feet are the most susceptible to cold injury primarily because they have a high surface to volume ratio, which makes them efficient at radiating heat. In addition, your fingers and toes are the last stop on the circulatory system’s route and the warm blood from the body’s core has cooled by the time it gets to them. Your toes are at further risk because they can also lose heat by conduction against the cold ground, ice or snow.

If your feet or hands are cold, now is the time to do something about it. If you don’t, you may be heading for frostbite. If you still have the sensation that an extremity is cold or even feels “freezing,” you have not yet entered frostbite. As the skin cools, blood flow decreases creating that cold or freezing feeling. As your skin continues to cool, a protective reaction called cold-induced vasodilation (CIVD) occurs. CIVD is also called the “Hunters Response.” Your blood vessels will dilate at short intervals to bring warm blood to the skin’s surface. Eskimos and Nordics have developed a strong CIVD response. However, if the skin temperature continues to lower, circulation will withdraw completely from the surface and CIVD will stop. The heart and core organs are not as efficient as the cold blood is circulated through them so the brain shuts off the blood flow from the extremities in order to protect the organs of higher priority.

The initial stage of frostbite is when your skin starts to feel numb due to the lack of blood flow. However, numb skin is not necessary frozen. To test for actual freezing, dent the skin with your finger nail. If it remains dented, you have superficial freezing, which can be passively re-warmed. You can vigorously shake your hands or whirl wind your arms to restore blood flow. Although a bit harder, you can do the same with your feet and toes. Once the feeling returns, head for warmth as soon as possible.

Re-freezing after initial warming can cause permanent damage to blood vessels and nerves. If you attempt to dent the skin with your nail and you can’t, the underlying tissue is frozen. You now have a serious medical emergency. Initial treatment for frostbite is to warm the part as fast as possible without causing any damage to the tissue. The best method is to use warm water. Water transfers heat 30 times faster than air and won’t damage the fragile frozen tissue. Passive re-warming by shaking can damage tissue and warming by radiant heat (holding the frozen part over a warm fire) isn’t fast enough. The water should be just warm, not hot, and circulated or changed to maintain a constant warm temperature until feeling occurs. The thawing of a frozen body part will be very painful. As the re-warming occurs, you can gently wiggle your toes or fingers, but do not massage them. After the feeling returns, protect the digits with dry cloth and immobilize while on the way to a medical facility.

Hypothermia, a condition where your body is losing more heat than it can produce, is an often talked about environmental injury. The initial stages of hypothermia simply include constant and uncontrollable shivering. The person or child is still alert and coordinated but just can’t stop shivering on their own.

If introduced into a warm environment, with dry clothes and a hot drink, the condition quickly subsides. However, there is a fine line between stage one and stage two hypothermia. In stage two, continued exposure to the cold affects the brain’s metabolism. In addition, the cold heart is much less efficient at pumping oxygenated blood to the brain and vital organs. Slurring of speech, loss of coordination and confusion will occur. In stage two, the shivering has stopped. Re-warming a stage two hypothermic requires the placement of heat packs against the torso, under the armpits and against the neck. Never warm the extremities first or massage a stage two victim. Massaging the skin of the extremities will only stimulate circulation returning very cold blood to an already overworked and oxygen deprived heart, which can trigger ventricular fibrillation. Stage two hypothermics should be evacuated immediately.

In stage three, or profound hypothermia, the body is stiff and unresponsive. Attempting to re-warm a stage three victim in the field is not practical. Re-warming in the field will most likely result in a sudden drop in heart temperature (when the very cold blood from the arms and legs returns) causing cardiac arrest. The recommended treatment for a person in profound hypothermia is to prevent further heat loss by removing all wet clothing and wrapping the person in warm clothing, linens, sleeping bag, etc with immediate evacuation. All hypothermics should be handled very gently as a jar to the cold vital organs can damage them.

The best treatment for cold injuries is to recognize the early warning signs and take action. It also wouldn’t hurt to watch the others around you while on the ski slope or snowmobile trail. Often, in a group setting, when one person is struggling and the others are not, that person’s first reaction is to cover it up. Speak up if you think someone is in trouble and help them out. Sometimes a warm drink, energy bar and an extra stop is all it takes.

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