#268105 - 03/15/14 03:22 PM
Hypothermia
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Old Hand
Registered: 11/09/06
Posts: 870
Loc: wellington, fl
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Temperatures have plunged here in the Sunshine State, reaching night-time lows approaching 50 degrees, presaging the entropy death of the universe...which brought this to mind: cold water boot camp Based on the data presented, you slim fit types will float off this mortal coil in 10 hours of submersion, while us full figured folks will bob around like walruses for a day and a half, reminding us that survival value is highly situational.
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Dance like you have never been hurt, work like no one is watching,love like you don't need the money.
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#268109 - 03/15/14 05:27 PM
Re: Hypothermia
[Re: nursemike]
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Enthusiast
Registered: 02/01/14
Posts: 310
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But I don't wanna die in cold water. Lol. Seriously, this opened the little woman's eyes about going over water in Alaska. I foolishly pointed out that she had more body fat than I do, in the right places of course, now I'm on the doghouse. I seem to recall AKSAR saying that that survival times in cold water were a lot less than ten hours. I'm just guessing by his name but he would seem to know a lot on the subject. JMHO. Thanks for the link.
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#268113 - 03/15/14 07:18 PM
Re: Hypothermia
[Re: Deathwind]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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How long you survive in cold water depends on a number of circumstances.
Water temperature: The experts define "cold water" as anything below 70 F (21 C). That might seem somewhat warm, but the reason they use that number is because that is the water temperature in which you can maintain your body temperature more or less indefinately. Below that water temperature, your body will gradually loose heat and you will eventually become hypothermic. How fast you become hypothermic obviously depends on how cold the water is. You will live longer in Florida than in Alaska.
Flotation: In cold water, you loose strength and dexterity in your arms and legs long before your core becomes hypothermic. When your arms and legs give out you can no longer swim or tread water. Without a life jacket you will drown long before your core becomes hypothermic.
Gender and body type: There are small differences due to gender and body type. Skinny people get hypothermic slightly faster than well padded people. Men typically get hypothermic slightly faster than women. These differences are generally very small however.
This has led to the One:Ten:One principle for very cold water.
"One Minute" When you fall in cold water your first reflex will be gasping and hyperventilation. This can last from seconds up to a minute. Your first priority is to get your breathing under control and to not inhale any water.
"Ten Minutes" In really cold water you have about ten minutes of useful motion to save yourself. You can swim, grab a lifeline, etc. After about ten minutes you will no longer have effective use of your arms and legs, and without floatation you will drown!
"One Hour" With a life jacket, it will take at least an hour before your core temperature drops to the point of dangerous hypothermia. (Even in the coldest water, some people with life jackets have been successfully rewarmed even after a couple of hours.)
One:Ten:One is obviously an average, and assumes very cold water like we have in Alaska. In other areas, like Florida, the "One Minute" gasping reflex might be shorter, or not happen at all. Likewise the "Ten Minutes" of useful motion and "One Hour" time to hypothermia might be much longer.
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"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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#268114 - 03/15/14 08:40 PM
Re: Hypothermia
[Re: AKSAR]
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Old Hand
Registered: 11/09/06
Posts: 870
Loc: wellington, fl
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Brain-eating amoebae in fl jelly fisg stings in fl shark attacks in fl Here in Florida, we don't actually get to stay in the water long enough to get chilly.
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Dance like you have never been hurt, work like no one is watching,love like you don't need the money.
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#268117 - 03/15/14 09:12 PM
Re: Hypothermia
[Re: AKSAR]
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Enthusiast
Registered: 02/01/14
Posts: 310
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AKSAR
Hence my search for a vest loaded with signaling and survival gear. But Mike had a link to Cold Water Boot Camp So my concern with cold water in this thread. I remember you explaining part of this to me on my thread Looking For A Special PFD. Thanks for the expanded information. I've been looking for similar information in the waters of the tropical islands. But have had no luck.
Mike
At least your sharks are native,free range like the neighbors chickens who devastated my gardens and yards. Months ago I saw an article where they were turning Sharks loose off the coast of Cape Cod, 14 of them I think, including some great whites.
Edited by Deathwind (03/15/14 09:17 PM)
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#268122 - 03/15/14 09:59 PM
Re: Hypothermia
[Re: Deathwind]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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I've been looking for similar information in the waters of the tropical islands. But have had no luck. As I indicated, in warmer water you last longer. I seem to recall reading that in WWII in the S Pacific, some sailors floated in lifejackets for 24 hours or longer, and survived. In that case, as Nursemike indicated, sharks and other marine life become bigger issues. Not to mention sunburn, dehydration, skin damage due to prolonged water immersion, etc etc. Any estimate of survival time in water (cold or otherwise) is just an educated guess. In Alaska the USCG routinely searches for people in the water a good deal longer than the charts would suggest you could survive. They like to give you the benefit of the doubt.
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"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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#268124 - 03/15/14 10:23 PM
Re: Hypothermia
[Re: AKSAR]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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You're not dead until you're warm and dead.
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#268137 - 03/16/14 03:11 AM
Re: Hypothermia
[Re: AKSAR]
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Geezer in Chief
Geezer
Registered: 08/26/06
Posts: 7705
Loc: southern Cal
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" I've been looking for similar information in the waters of the tropical islands. But have had no luck."
There is an interesting map in one of the classic survival texts, "The Survival Book", by Paul Nesbitt, Alonzo Pond, and William Allen, 1959. On page 11 is a diagram titled "Expected Time of Survival of Men Immersed in the Sea -February. They depict Area F - Indefinite (depends upon fatigue)- basically area F is everything between the Tropics of Cancer and Capricorn. Alaska falls into Area A-less than 3/4of an hour. Off coastal California (area D) survival is less than 6 hours. These times are for men in "ordinary clothing and a life preserver". They say nothing about those in the population with properly distributed fat....
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Geezer in Chief
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#268142 - 03/16/14 04:31 AM
Re: Hypothermia
[Re: hikermor]
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Enthusiast
Registered: 02/01/14
Posts: 310
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Hmmmm interesting. Thanks hikermor
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#268144 - 03/16/14 05:11 AM
Re: Hypothermia
[Re: hikermor]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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In WWII during Typhoon Cobra (AKA "Halsey's Typhoon"), at around Latitude 15 deg in the Phillipine Sea, three US Navy destroyers were sunk and 790 sailors died. Remarkably a few survived, 62 from the USS Hull, 6 from the USS Monahan, and 23 from the USS Spence.
While a few of these survivors were on small rafts or other debris, the majority of them were floating in kapok life jackets. Many were in the water for more than 48 hours. The last survivor recovered alive was from the Spence, which capsized and sank around 1100 on December 18. He was spotted floating in his life jacket on the the afternoon of December 21.
The book "Halsey's Typhoon" (2007) by Drury and Clavin is a good read.
_________________________
"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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