#87565 - 03/06/07 08:58 PM
Re: Survival Myths
[Re: Susan]
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Newbie
Registered: 02/01/07
Posts: 48
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I need a math check....
A calorie is defined by "Any of several approximately equal units of heat, each measured as the quantity of heat required to raise the temperature of 1 gram of water by 1°C from a standard initial temperature, especially from 3.98°C, 14.5°C, or 19.5°C, at 1 atmosphere pressure."
1 Liter of water = 1000 grams
From article "As far as the temperature of the liquid is concerned, it is more comforting to drink a warm liquid in the cold. But, think of the physics. Take an average man, weighing about 170pounds (80kg). Since we are 70% water, that 170pound (80kg) man is 120pounds (56kg) of water or 15 gallons (56liters) of water (one gallon of water weighs 8 pounds). So, if you were to take 1 quart (1 liter) of hot tea water at 110ºF (43.3ºC) and pour it into 15 gallons (56liters) of cool water at 90ºF (32.2ºC), it will raise the temperature from 90ºF (32.2ºC) to 90.3ºF (32.4ºC), not enough to make a clinical difference. But, if instead, you throw into that 170pound (80kg) man, 1 quart (liter) of a fluid containing sugar, now he has fuel to put into the furnace to burn, to get warm, stay warm, shiver, function, survive, and thrive."
In order to raise your temp the same amount (56 liters (56000 grams), 0.2*C) would require you to consume 2,800 calories to do the same thing as drinking the hot tea. Correct?
If calories are life the guy drinking the tea is going to live longer than the guy drinking cold sugar watter.
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#87567 - 03/06/07 09:07 PM
Re: Survival Myths
[Re: Meline]
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Newbie
Registered: 02/07/07
Posts: 36
Loc: Salt Lake City, UT
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In order to raise your temp the same amount (56 liters (56000 grams), 0.2*C) would require you to consume 2,800 calories to do the same thing as drinking the hot tea. Correct? Not exactly. The 'calories' we use to measure energy in food area actually kilocalories (1000 regular calories). So it only takes one food calorie to raise the temperature of 1 liter of water 1 degree Celsius. Raising 56 liters of water 0.2 degrees would require 11.2 calories of food (assuming the conversion from sugar to body heat were 100% efficient, which it isn't).
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#87569 - 03/06/07 09:11 PM
Re: Survival Myths
[Re: OldBaldGuy]
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Journeyman
Registered: 01/07/05
Posts: 86
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I used to teach a course in micro-climatology, and things like wind chill and hypothermia were a small part of it. At several points in the course I would paraphrase from the Monty Python sketch about Dennis Moore:
"Blimey, this redistribution of heat is trickier than I thought."
_________________________
“Expectation strolls through the spacious fields of Time towards Opportunity.” Umberto Eco
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#87571 - 03/06/07 09:30 PM
Caffiene products will only further dehydrate you
[Re: Lasd02]
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Member
Registered: 07/18/06
Posts: 178
Loc: Springfield, MO
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Another myth that I have heard:
Is that if you are dehyrdrated you would be worse off drinking soda because it has caffiene in it. I've read recently that that is not true. After doing a study they determined the end result after the body has processed the caffiene is you would still get a net 70% (if I remember right) increase in water. Not as good as drinking 100% water, but still better than not drinking it at all...
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#87572 - 03/06/07 09:39 PM
Re: Survival Myths
[Re: Frozen]
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Member
Registered: 07/18/06
Posts: 178
Loc: Springfield, MO
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Don't forget the diuretic effect of tea and coffee. Dehydration is a factor in hypothermia as well I read recently that this effect isn't as bad as it once was thought to be. You do lose some of the fluid due to the diurectic effect, but if that's all you've got to drink then drink it. This isn't the study I read, but is another example: caffiene research
Edited by Micah513 (03/06/07 09:43 PM)
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#87587 - 03/07/07 01:08 AM
Re: Survival Myths
[Re: Blackeagle]
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Cranky Geek
Carpal Tunnel
Registered: 09/08/05
Posts: 4642
Loc: Vermont
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And you are most worried about warming up the moving fluid, blood, that has nice big pipes that are near the digestive tract. Short of a nozzle and some piping, I can't think of a more effective way of doing that.
_________________________
-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.
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#87619 - 03/07/07 05:18 AM
Caffiene and alcohol
[Re: Micah513]
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Registered: 01/23/07
Posts: 20
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You are so right. The people who claim that drinking caffienated beverages is worse than drinking nothing at all are totally off base, and I was glad to see that old adage debunked in a fairly recent National Geographic article. Along the same line, I've often heard that drinking alcoholic beverages are worse than drinking nothing at all. But just put me in Death Valley for 3 days with 3 cases of beer along with the nonalcoholic bloke who drinks nothing at all and see who comes out healthier--and happier. I don't doubt that plain old water is better for hydration purposes, but many 19th century sailors and some of my friends have proved that you can survive for extended periods without drinking it.
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#87624 - 03/07/07 06:38 AM
Re: Caffiene and alcohol
[Re: Menawa]
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Journeyman
Registered: 01/16/07
Posts: 60
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The wilderness article states that drinking a liter of warm liquid will raise your core body temp 0.3 degrees. A cold liquid will lower it by the same amount. A very hot liquid may raise your temp even more. This 0.6 to 1.0 degree difference in core temp is very very significant. Why they think this is insignificant is beyond me. It is so important that the joint commision for hospitals is requiring the collection and reporting of data on mild hypothermia postoperatively for surgical patients and extra efforts are being used to prevent even mild hypothermia in the operating room. Even a couple of degrees makes a huge difference in bloods ability to clot in a trauma situation. Also the "fact" is that surface area is not the common denominator for heat loss. Due to differences in radiation, insulation, conduction, convection, blood supply and autoregulation your head loses a lot more heat under almost all circumstances than your fat ass.
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#87628 - 03/07/07 08:00 AM
Re: Caffiene and alcohol
[Re: Menawa]
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Geezer
Registered: 01/21/04
Posts: 5163
Loc: W. WA
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If the average regular beer is 5 percent alcohol and has 43 calories per 100 ml, the rest is probably water. So you'd be better off drinking it than not drinking anything. Well, unless you drink so much that you walk off a cliff or something. And the calories would probably help your digestive system absorb the water faster than drinking just plain water.
Beer: The Desert Health Drink
Sue, who can't even get past the smell
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#87666 - 03/07/07 07:06 PM
Re: Caffiene and alcohol
[Re: TomP]
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Member
Registered: 12/14/05
Posts: 130
Loc: Pasadena, Calif.
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I'm glad to see that many of these issues are being discussed and debated. Not that you need me to point it out but everyone's comments are welcome and valid, the problem arises when we confuse "opinion" with "fact". Anyone is welcome to disregard the experts and continue to believe anecdotes or a one time personal experience but If you chose to do so, Isn't it your responsibility to point that out and prevent confusion? You start with a claim that hospitals are keeping track of hypothermia data for post operative patients and that the .6 degree difference is vitally important, great, if that's the case more power to them, but what does that have to do with the benefits of drinking a calorie laden cold drink over a cup of hot tea in a survival situation? I suppose if your BOB is equipped to handle open heart surgery this may be an issue but I would bet that for the majority of us this isn't the case. Then you go on to make this statement: Also the "fact" is that surface area is not the common denominator for heat loss. Due to differences in radiation, insulation, conduction, convection, blood supply and autoregulation your head loses a lot more heat under almost all circumstances than your fat ass. If this is in fact true, I would love to see what you base it on so I can re-evaluate my position, until then I will stick with the experts in this field. 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. 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. The rate of heat loss is relatively the same for any exposed part of the body, not simply the head. You do not lose heat significantly faster through the scalp than any other portion of the body with the same surface area.
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