Archive for October 26th, 2006

Introduction to Frozen Mythbusters and Myth #1

October 26, 2006

Frozen Mythbusters: Myth #1 of 13.
There are a variety of myths regarding human response to cold exposure.  These myths are explained and debunked by Dr. Murray Hamlet, DMV, Dr. Gordon Giesbrecht, PHD, and Frank Hubbell, DO.  After posting the thirteen myths, a complete article  from the Wilderness Medicine Newsletter will be loaded for anyone interested in all the chilly little details.

The following is reprinted from Volume 15 Number 6 of the journal Wilderness Medicine Newsletter from November/December 2004. 

Recently, I (Frank) had the delightful opportunity to spend several days with Gordon and Murray as we taught together at the Northern NH EMS Conference and the Harry McDade Hypothermia Conference. As usual we took great joy in the opportunity to discuss current research, current classroom information, and a variety of rescues involving hypothermia and other cold-related injuries. We recognize that even though there is abundant scientific information, there are still many old wives’ tales and misinformation that are being taught, passed on, and utilized in patient care. There appears to be some bad data in education which is causing rescuers to provide inappropriate patient care that can be deleterious to their patients. So, we decided to take a look at the many myths and misinformation that seem to surround cold physiology and cold-related injuries.
Frozen Myths to be Busted
If you fall through the ice, you will die of hypothermia within 5 – 10 minutes.
If your feet are cold, put on your hat.
Warm water or a cup of hot tea will keep you warmer then a glass of soda or orange juice.
Rubbing frostbite is the proper and best way to rewarm frozen parts.
Hypothermia is a disease, the severity of which can be determined by the amount of shivering, and shivering is bad.
You should never actively rewarm a hypothermia victim in the field because you could cause massive peripheral vasodilation, cardiovascular instability, and ventricular fibrillation.
Frostbite is rarely associated with hypothermia.
Hypothermia is an absolute emergency.
If a hypothermia victim is found breathless and pulseless, you should immediately begin CPR and access ACLS as soon as possible.
Hypothermia victims are not dead until warm and dead.
The best way to rewarm a hypothermia victim is to place them naked in a sleeping bag with a warm, naked rescuer so they can share body heat.
There is no such thing as “after drop” while rewarming a hypothermia victim.
Exposing the patient to remove cold wet clothing will cause a large drop in their core temperature.

Myth #1
 If you fall through the ice, you will die of hypothermia within 5 – 10 minutes.
If you live in Alaska or around any large body of open, cold water, then you have probably heard this statement dozens of times. It is usually spoken with a curled eyebrow and a facial expression to reinforce the fact that anyone with half a brain knows this. Well, guess what? It’s a bold-face lie. The reality is that you simply cannot die of hypothermia in 32ºF (0ºC) water in 5 – 10 minutes. However, there are several possible scenarios that can lead to a rapid demise if you fall through the ice or fall into the icy waters off Kodiak Island in Alaska:
A. The individual has just broken through the ice, is now gasping for air, panics, sucks in water, and drowns within the first minute or two.
B. They survive the initial gasping for air, but then over the next 10 minutes, their muscles and nerves become cold and ineffective, and they are no longer able to tread water. If they are not wearing a personal floatation device, their head and airway will slip beneath the surface of the water, and they too will succumb to the deep and drown.
C. They manage to hang onto the ice or stay afloat. Over the next hour or so they shiver and slowly cool off. Eventually they will lose consciousness, at which point if their arms, beard, or other part of their anatomy is NOT frozen to the ice, they will slip below the surface and disappear into the depths.
D. They did not panic; they were able to hang on and keep their head above the water even after they lost consciousness (if frozen to the ice). Then and only then, if not rescued in the next hour or two, they may indeed eventually develop severe hypothermia and “freeze to death.”

Professor Popsickle (aka Gordon Giesbrecht) summarizes the through-the-ice experience, which, by the way, he has personally undergone many times including on The Late Show with David Letterman, (what a ham), with the expression “1 minute…10 minutes…1 hour…2 hours,” to remind us of what happens to humans when they are plunged into very cold water (i.e. 320F or 00C). This
1 Minute – Ten minutes – 1 Hour – 2 Hours

One Minute to Control Your Breathing. The initial reaction is a gasp reflex, where for about one minute the individual will gasp for air in reaction to the cold water. As the cold reaches the skin, the peripheral vasculature vasoconstricts forcing the blood in the skin back into the body core which creates an insulating barrier against the cold. The trick is not to panic and start thrashing about. Just slowly tread water or grasp the edge of the boat or ice to keep you head above the water. After approximately one minute the gasping will calm down, the skin will become numb, and the sensation of intense cold will decrease.

Ten Minutes of Meaningful Movement. Now you have about 10 minutes to get out of the water. Gordon has worked out a simple method to help you get up onto the ice. Keep your hands and arms on the ice and kick your feet. This will bring your body to a horizontal position, parallel to the ice surface. “KICK AND PULL.” Once horizontal, kick with your feet while pulling with your hands. You will be able to propel yourself up onto the ice. I would suggest that at this point, you should not stand up as the ice may not support your weight. Instead, try to keep your weight spread out as you roll, crawl, and slide across the ice until you know it will support your weight.

One Hour Before You Become Unconscious. If you were unable to get out of the water, after 10 minutes or so, the muscles in your arms and legs will become progressively useless due to heat loss in the extremities. Consequently, you will not have the strength to get out of the water. Unless there is someone else to help, you’re stuck. All is not lost, however. You will feel pretty numb and you will shiver (this is our normal physiological response to the cold, an effort to produce more heat than we are losing). You will remain conscious for about one hour. How long you remain conscious depends upon the clothing you are wearing, energy stores, and body build. Eventually you will lose consciousness as your body core temperature decreases to about 86º F (30ºC). Unless you slip below the surface and drown, you are still a long way away from death due to hypothermic cardiac arrest (core temperature below 82.4ºF/28ºC).
 Two Hours to Be Found. If you lose consciousness but do not slip below the water, you can still be successfully rescued if you are found within two hours or so. So, forget that old myth that you only have ten minutes if you fall into ice-cold water-that myth has been busted. 

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