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Author Topic: Is skin burned only at an absolute and not a relative high temperature?  (Read 4389 times)

Offline Astronomer_FB

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Since how hot something is  is a relevant thing if your hands were really cold lets say -100 F  if you were to wash your hands in 0 F would it burn your hand? And forget the frost bite your hand would get  this is just a relly extreme example.
« Last Edit: 09/03/2009 22:14:19 by chris »


 

Offline Chemistry4me

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It would hurt like heck.
 

Offline JnA

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it would 'burn'.. but wouldn't hurt until the pain receptors started to work again (if at all)

In first aid we are warned to 'gently and slowly raise body temp' of someone who has been exposed to extreme cold.
 

Offline syhprum

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During the war the Nazi,s did experiments on concentration camp inmates to find the best way to revive fighter pilots who had been shot down into the cold waters of the channel.
They came to the conclusion that immersion in real hot water about 45C was best but I don't know how that compares with modern thinking
« Last Edit: 10/03/2009 06:43:19 by syhprum »
 

Offline LeeE

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Washing your hands in 0 F water isn't possible because it freezes at 32 F, but in any case, washing your hands in cold water won't 'burn' them because the cold water won't do any damage to them.  It might be very painful indeed, but this is because of the pain receptors thawing out and starting to work again.  Any damage though, will have been caused by the freezing, not by the thawing.

I believe that you're supposed to raise body temperatures slowly to stop chilled blood from the peripheries rushing back to the heart where it could potentially shock it in to stopping.

This question probably belongs in the Life Sciences section.
 

Offline JnA

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freezer burn?
 

Offline Astronomer_FB

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Washing your hands in 0 F water isn't possible because it freezes at 32 F, but in any case, washing your hands in cold water won't 'burn' them because the cold water won't do any damage to them.  It might be very painful indeed, but this is because of the pain receptors thawing out and starting to work again.  Any damage though, will have been caused by the freezing, not by the thawing.

I believe that you're supposed to raise body temperatures slowly to stop chilled blood from the peripheries rushing back to the heart where it could potentially shock it in to stopping.

This question probably belongs in the Life Sciences section.
I was trying decide but i couldn't I'll make sure to think about it a liitle bit more before i post.
 

Offline yor_on

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LeeE I think you're on the 'spot' there. This was found out under the second world war, I think, when all those transport ships were sunk in the Atlantic. You basically sweep in the guy/gal in a towel covering the torso leaving the extremities free to the air and let the body heat from that warm up the rest.

I wonder if it wasn't also that you wanted to get the blood running more slowly to the extremities too so not to lose fingers and toes to frostbite? What happens when you get extremly cold is that the blood will be withhold to support only the most important functions for surviving, that means that the blood will, to a large extent, be stopped from wandering out to the extremities of your body like legs and arms and instead be kept in the torso. I have this vauge memory that if you warm those peripheral parts up to fast the blood might clot or get stuck in some other way, leading to you losing body parts?

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Syhprum, going from being ice cold to be dipped into a 45 C degree bath sounds like a sure try for a heart attack to me :) Are you sure on this?
« Last Edit: 09/03/2009 16:50:39 by yor_on »
 

Offline LeeE

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I believe that the problem of frostbite occurs when the cells freeze and expand, physically bursting the cell walls.  I think the lack of oxygenated blood is less of a problem because locally, the metabolic rate has dropped so low that it's not needed.  I'm not sure about clotting/blockage risks; it's just not something I've come across.
 

lyner

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I thought it was the lack of oxygenated blood that allowed gangrene to develop. Bad news!
 

Offline yor_on

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I looked for it on the net, this is what I found. I think that I'm correct in that if you have frostbite the extremities should be warmed up slowly as is the case with treating hypothermia too. But it's definitely the chock to the heart by to cold blood that is the most dangerous case here by warming up a person to fast.

" Water removes heat from a body 25 times faster than cold air and most of the body heat is lost through the head. Swimming, thrashing about, and other physical activity increases the heat loss through the limbs and extremities. If you become a person in the water (PIW) you will sharply reduce your survival time though physical activity. Strong swimmers wearing a PFD have died before they covered 100 yards in cold water. Did you know that in water with a temperature of less than 40 F., a strong man can expire before he can swim 100 feet? Two factors come into play against you while you are immersed in cold water: they are cold shock and hypothermia. "

"Hypothermia (death from loss of body heat) may occur following immersion in water with a temperature less than 68oF (20 C). A healthy person in ordinary clothes and wearing a lifejacket would have an expected survival time of less than three-quarters of an hour at temperatures less than 35oF (1.6 C), less than 1 1/2 hours at 35-40oF (1.6-4.4 C), and less than 3 hours at 40- 60oF /4.4- 17.5 C)."

Severe hypothermia symptoms show shivering probably stopped, victim resists help or may be semi-conscious to unconscious. Victim must be kept prone, on back and immobilized.

Cover torso, head, neck and thighs with dry covers to stem further heat loss. Do not stimulate arms and legs in any manner. Cold blood returning to the body core may cause cardiac arrest. Some apparent drowning victims may look dead, but may actually still be alive!
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A phenomenon called the "mammalian diving reflex" can be triggered by cold water. This reflex, common to whales, porpoises and seals, shuts off blood circulation to most parts of the body except the heart, lungs and brain and slows the metabolic rate. What little oxygen remains in the blood is circulated where it is needed most.!
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Look for signs of pulse or breathing during first two minutes. If pulse or breathing are found, even in trace amounts, DO NOT start CPR. In this state, CPR can cause cardiac arrest. If you cant find a pulse or sign of breathing, CPR should be started only by a trained and qualified crew member. Rush victim to nearest medical facility by best means available."

And finally :)

How humans deal with and survive extreme cold
http://www.coolantarctica.com/Antarctica%20fact%20file/science/cold_humans.htm
« Last Edit: 09/03/2009 23:06:55 by yor_on »
 

Offline syhprum

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This is a very old story that I read shortly after the war it may only have been spread to show how inhumanly the Nazis treated concentration camp inmates.
 

Offline yor_on

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Those idiots probably did it, there are always some people that love playing gods, and the Nazis was full of that kind of losers.
 

Offline Astronomer_FB

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Washing your hands in 0 F water isn't possible because it freezes at 32 F, but in any case, washing your hands in cold water won't 'burn' them because the cold water won't do any damage to them.  It might be very painful indeed, but this is because of the pain receptors thawing out and starting to work again.  Any damage though, will have been caused by the freezing, not by the thawing.

I believe that you're supposed to raise body temperatures slowly to stop chilled blood from the peripheries rushing back to the heart where it could potentially shock it in to stopping.

This question probably belongs in the Life Sciences section.
i didn't say it was water that you washed your hands in but you get the point anyway.

If you were to be in the cold water and you got out i heard what you do is take off the wet clothing and then lay on your back in the Fidel position. is this true?
 

Offline yor_on

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What exactly might Fidels position be on this?
You definitely need to get rid of those wet cloths though, no matter how cold it is in the air. And wring them out as good as you can, I've heard that wool is a good material to wear if it is loosely knit, it will trap the air and keep the warmth even if damp?

But water leads you body heat away 25 times faster than cold air. If someone pass you, just act relaxed, try to look inconspicuous but remember to wave frantically as you're doing your push ups :) Hopefully they will take the hint and come for a closer inspection.

 

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