Companion forum thread to:

Hypothermia

Good article.

The actions on the part of the scout leaders at the beginning of the article are shocking to me though.

A must-read for anyone who ventures out of their own warm little nest. It should be considered a Classic article here at BPL


I STRONGLY RECOMMEND THIS ARTICLE BE "PINNED" SO IT NEVER LEAVES THE HOME PAGE OF THE BPL WEBSITE.

Due to the potential life-saving benefit inherent in this article, I further recommend that it be made available to ALL visitors, not just the Premium Members.

Edited by wandering_bob on 05/07/2008 07:45:28 MDT.

Great timing as well, as it is starting to be prime time backpacking season. Here in the San Juans in Colorado, July is the most common month for hypothermia - more people are out there, it is blue skies in the morning, then afternoon thunderstorms come in when the jeans and cotton t-shirt sweaty hiker (without rain gear...) is well above treeline on a popular 14er,... and they are hypothermic. Consider fire starting to be the first survival item to come - firesteel and a few tinderquicks vacuum sealed for emergency fits in a pocket and weights almost nothing, but can save your life.
and dress smart!

Great article!! Describing these concrete personal examples of mental and physical befuddlement can really help folks recognize their own symptoms of hypothermia. Most resources just list general symptoms (declining mental status, etc.)that can seem like abstract concepts to non-medical personnel. This should be linked or forwarded to scouting groups, pcta.org,.....

I would only add 2 words (which I learned from the Seattle Mountaineers 20 years ago)---COTTON KILLS !!!!

Folks,

Make this available to all site visitors. This might save someones life someday.

john the xcar

a couple more things:
boil/heat some water, put it in bottles that can handle hot liquids, and insulate the bottle so it does not burn the patient, then put it in the hypo wrap with them. patients in moderate hypo or worse really need external heat applied, getting in with them only makes you colder, and most of us don't carry chemical heat packs! so boil water. since you probably didn't bring extra fuel, you might need to build a fire for this, which would also help in its own right. I took a Wilderness First Responder course this February, in the San Juans. It snowed almost every day, and we had 3-4 feet of snow. Many of our scenarios were done in deep snow and cold, including a long 4-5 hour night scenario, with temps near zero. Often when a person has other medical issues, hypothermia can QUICKLY become a life threat, so think preventatively and get them warm before they cool off. Don't compound a medical emergency, and the potential for shock with hypothermia as well. Most major accidents are a series of smaller mistakes where the net effect is worse than the sum of the parts.
and practice building fires in all conditions, with many different fuels.

Excellent article Darin, very well done.
Leading a group of new folks out next weekend and this will be their "required" reading
Thanks
Jim

Many thanks Jim. It's good to hear you're getting out. Your group is lucky to have your knowledge and great personality. I hope everything goes well.
Darin

A very minor quibble concerning an otherwise very nice article.

In the article there is a mild confusion between the first and second laws of thermodynamics, and the role of entropy. Schroedinger's book is not entirely clear, which is likely the cause.

As far as hypothermia is concerned, entropy is irrelevant. All that matters is energy balance. You need energy to heat yourself up, you either get it from yourself or you get it from an outside source.

I'm backpacking above 10,000' this weekend so the information is timely. Thanks to the article I now know what happened to me a couple of years ago while hiking a local summit. In a final long push to make it to my campsite I didn't eat or drink, figuring I would do so at camp. I was moving fast and didn't feel cold. But as soon as I stopped I began to feel groggy. I tried to cook a quick meal but I could barely get the stove out. Lighting a match was almost impossible. I began shivering and couldn't think clearly. How could I have become so cold so quickly, especially since I was bundled up? I now realize that lack of food and water contributed greatly to my condition. Thanks for an informative write-up.

Outstanding article, really excellent information, only.. it is somewhat misleading to comment on having a mildly hypothermic person get in the sleeping bag: according to your chart, a mildly hypothermic person already has "mild shivering".

Only the warmest person gets in the sleeping bag: this is "tested" by an ungloved hand on a bare belly to "discover" who is the warmest person.

Been there, I have seen that done successfully.

Maybe some people are embarrassed, however I know one person alive because it was done right.

Edited by ConnieDodson on 05/09/2008 06:16:28 MDT.

Thanks for the article. We're headed out for four days tomorrow. Nice to have this refresher about what action to take and to increase our awareness.

Ditto to all of the above comments, and esp. John Smith

Lessons learned:
Try not to hike alone in the winter, because each can keep an eye on the health of the other. Hiking alone, the symptoms of hypothermia are hard to stop alone once they start. Ever have a drunk friend try to convince you he/she can drive? A hypothermic person with impaired judgement might not think he/she is cold... IGNORING THE SYMPTOMS!

Take overnight gear on day hikes. (bivys, tarps, pads, bags, headlamp)

Edited by rambler on 05/09/2008 10:14:23 MDT.

Why do humans become so badly affected by a small fall in core temperature (37 to 30 C seems a small change of 7C but might be fatal: why should your brain stop working when cold:

reptiles just become slower/sluggish when cold.

This seems a bit of a flaw in mammals.


I didnt notice any mention of paradoxical undressing.

Not in all mammals...how about the Ice Man

Great information - I really appreciate this type of article from BPL.

I have personally experienced mild/moderate hypothermia on one occasion while rafting on an unseasonably warm May day. Air temps were in the 80's, but the water was direct snow melt and the creek I was on was soaking me frequently. I skipped the splash gear because of the warm air temp, but the longsleeve synthetic tshirt I wore under my farmer john wetsuit was keeping my upper body wet and was zapping my energy. I did not take the time to eat anything, or stop to put on the splash top, as we were pushing to get down to the main river quickly and the whitewater was nearly continuous.

The group I was in were very experienced all-season Class V+ boaters. I maintained that I felt fine, that I was just a little chilled, and I had a major adrenalin high going because of the challenging high water conditions. It wasn't until I attempted to step out onto shore to scout a major rapid that I realized that I had lost significant coordination, was experiencing numbing of the extremities, and was slightly confused and apathetic. And when I unzipped my PFD, I immediately began to shiver uncontrollably, which is what suddenly alarmed me.

I had read extensively on hypothermia and the signs and stages prior to that trip, and somehow I finally recognized the symptoms on myself, but only after it got to a potentially dangerous level. What if we wouldn't have had to stop when we did? What if we would have flipped, or I had fallen out of the boat?

My rewarming was fairly simple, but it probably took 30 to 45 minutes. It seemed like longer. I replaced my wet tshirt, put on my dry splash top (with help), ate a granola bar, drank some water, and hiked 1/2 mile uphill to the overlook in the midday sun.

There were a lot of things I did wrong that day, and at least three smarter clothing combinations that I had with me, but that I didn't use in time. I am happy to say that I have learned my lesson - I will be wearing a drysuit when I return to run the same creek this coming Saturday.

This article has reminded me of some important stategies for helping those who are the victims of unforeseen circumstances, or who are caught unaware as I was that day.

Edited by jbrinkmanboi on 05/13/2008 00:47:25 MDT.

Good article, succinctly hits all the important points. Regulating core body temp is a fundamental skill that too often is lacking among those who venture into the boonies. I too find it unforgiveable that the leadership of the group described in this article was so inept. Had a death resulted from their incompetence, they could very likely have been held negligent in a court of law.

So, you guys/gals with kids who go out on outings beyond your direct supervision, make sure you check out those folks who will be leading the trek. There are way too many water-cooler Rambos out there these days and too few folks who watch "Man Versus Wild" uncritically. Death is death.

Book recommendation: "98.6 How to Keep Your Ass Alive", Cody Lundin. Think what you will of Lundin, his treatment of the the subject is excellent and should in every backpacker's library.

John

There is no alternate method for performing CPR on a hypothermic patient; Basic Life Support treatments for cardiac arrest and bradycardia do not change because the patient has a lowered core temperature. Below are the American Heart Association guidelines for CPR on a hypothermic patient, guidelines also used by the Red Cross:

Hypothermia
In an unresponsive victim with hypothermia, a healthcare provider should assess breathing to confirm respiratory arrest and assess the pulse to confirm cardiac arrest or profound bradycardia for 30 to 45 seconds because heart rate and breathing may be very slow, depending on the degree of hypothermia. If the victim is not breathing, initiate rescue breathing immediately.

If the victim does not have a pulse, begin chest compressions immediately. Do not wait until the victim is rewarmed to start CPR. To prevent further heat loss, remove wet clothes from the victim; insulate or shield the victim from wind, heat, or cold; and if possible, ventilate the victim with warm, humidified oxygen.

Avoid rough movement, and transport the victim to a hospital as soon as possible. If VF is detected, emergency personnel should deliver shocks using the same protocols used for the normothermic cardiac arrest victim (see Part 10.4: "Hypothermia").

For the hypothermic patient in cardiac arrest, continue resuscitative efforts until the patient is evaluated by advanced care providers. In the out-of-hospital setting, passive warming can be used until active warming is available (Class Indeterminate).

http://circ.ahajournals.org/cgi/content/full/112/24_suppl/IV-19

Edited by jgrafft on 11/26/2008 16:05:07 MST.

Jason,

Thank you for your comment on the article. The CPR protocol in the article is based upon the research of James Wilkerson, M.D. and Gordon Giesbrecht, Ph.D., who are widely recognized as the leading authorities on the physiological effects of cold on the human body, which is why I used their protocol in the article.

The American Heart Association protocol you cited is in fact an alternate method for performing CPR on a patient that has a lowered core temperature from the standard protocol listed on the same page:
o Assess breathing and pulse for 30 to 45 seconds instead of the standard 10 seconds
o Remove wet clothes from the victim; insulate or shield the victim from wind, heat, or cold
o If possible, ventilate the victim with warm, humidified oxygen
o Avoid rough movement

The main difference between the American Heart Association protocol and Wilkerson and Giesbrecht’s is that they recommend three minutes of ventilation because “such oxygenation may improve cardiorespiratory activity enough to be detected” thus eliminating the need for CPR, which could bring on cardiac arrhythmia if the heart is in fact beating. Use whichever protocol you are comfortable with.