Losing heat through the head a Myth !

pitdog

pitdog

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Seems it's a Myth about how much heat we lose from not wearing a hat !

Heat Loss Through the Head and Hypothermia
By wildernessmedicinenewsletter
The rate of heat loss, at rest, with exercise, and with hypothermia

Since there has been a fair amount of interest regarding Myth #2 in the Wilderness Medicine Newsletter – Frozen Mythbusters, Nov/Dec 2004 – the topic deserves more discussion.

MYTH #2 states. “If your feet are cold, cover your head because you can lose up to 75% of your body heat through your head alone.

The problem is that the head is only about 10% of the body surface area. Thus, the head would have to lose about 40 times as much heat per square inch or centimeter compared to the rest of the body.

Gordon had heard this statement one too many times and finally decided to see if this was indeed true. So he took several test subjects, all volunteers, of course, (you have to wonder what problem they caused at the university), wired them to monitor their core temperatures, and discovered that we do indeed lose heat through any exposed part of the body and the amount of heat we lose depends on the amount of exposed surface area. 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.

It is still a good idea to put on a hat (a hood really – what insulation does a baseball hat have?) if your feet are cold. But what is BUSTED is that there is nothing peculiar or unique about the head. The idea that we lose heat faster through out scalp, because of the constant blood supply to the brain, is simply a myth. (One that I personally have believed for many years.)”

Protecting the extremities is always a good idea though and in cold weather a hat is obviously an essential item.
You will never catch me in extreme cold without a hat !:thumbup:

p22300011.jpg

By pitdog2010 at 2011-02-23
 
"You can keep the hat on..."

chip_1476699c.jpg


You got nothin' new there Pit............................:D
 
Hmmm... well, given the fact that heat rises, and the head is the highest point of the body, and any heat lost is lost for good, I think I'll continue keeping a warm hat in close proximity.
 
That is interesting, it makes sense when you think about it that way.
If you were to lose 75% of your body heat through your head,
it would seem that your head would have to be 75% of your body's
surface! That is one big noggin!

It always amazes me that such simple misconceptions go unquestioned for
as long as they do. We as humans have grown accustomed to move on as
soon as we think we have come up with an answer.

Reminds me of the idea of a geocentric solar system, introduced by Ptolemy.
I find it funny that it was believed for as many centuries as it was.
 
probably should add this bit as well

"Now, what about hypothermia and heat loss through the head?
If the hypothermia victim is not shivering, they are at rest, and the heat loss through the head remains about 7%. But, this is important, if they are shivering, the percent of heat loss via the scalp can increase to upwards of 55%, so protecting the head well is a very important part of treating the hypothermia patient. And as you can imagine, the primary defense against the cold and hypothermia is vasoconstriction of the peripheral circulation, this shunts blood to the core, reduces circulation to the skin, and increases the percent of heat loss through the scalp."
 
Iboschi said:
Nice post pit! I can't believe you had the gall to wear shoes!
Click to expand...

Mrs Pit suggested it as an ' in joke ' with her friend....pic just seemed appropriate with the information posted !:D

Although the info says it's a myth I still find putting a hat on increases my general warmth more than putting extra layers on anywhere else. Likewise when I'm hiking uphill and starting to sweat I always find removing my hat allows me to cool down quicker than removing a sweater etc !
 
pitdog said:
Seems it's a Myth about how much heat we lose from not wearing a hat !

Heat Loss Through the Head and Hypothermia
By wildernessmedicinenewsletter
The rate of heat loss, at rest, with exercise, and with hypothermia

Since there has been a fair amount of interest regarding Myth #2 in the Wilderness Medicine Newsletter – Frozen Mythbusters, Nov/Dec 2004 – the topic deserves more discussion.

MYTH #2 states. “If your feet are cold, cover your head because you can lose up to 75% of your body heat through your head alone.

The problem is that the head is only about 10% of the body surface area. Thus, the head would have to lose about 40 times as much heat per square inch or centimeter compared to the rest of the body.

Gordon had heard this statement one too many times and finally decided to see if this was indeed true. So he took several test subjects, all volunteers, of course, (you have to wonder what problem they caused at the university), wired them to monitor their core temperatures, and discovered that we do indeed lose heat through any exposed part of the body and the amount of heat we lose depends on the amount of exposed surface area. 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.

It is still a good idea to put on a hat (a hood really – what insulation does a baseball hat have?) if your feet are cold. But what is BUSTED is that there is nothing peculiar or unique about the head. The idea that we lose heat faster through out scalp, because of the constant blood supply to the brain, is simply a myth. (One that I personally have believed for many years.)”

Protecting the extremities is always a good idea though and in cold weather a hat is obviously an essential item.
You will never catch me in extreme cold without a hat !:thumbup:

p22300011.jpg

By pitdog2010 at 2011-02-23
Click to expand...
do you listen to the village people?
 
While it's true that the head may represent only 10% of the entire body, it is frequently the only portion of a man's outfit that may completely uncovered. That 10% may be the 100%
openly exposed to the cold.
If the head has no protection from the cold, shouldn't it lose a larger % of heat then the chest that is typically covered by a scarf-sweater & coat?
My data is totally empirical, but I feel the cold less when wearing a cap and hood. I even wear a Balaclava, when it's in the teens or below.
 
The biggest thing I can do to keep warm below freezing is to wear a buff or chute around my neck. I can be wearing two hats, and I can still start to chill if my body heat is being stripped out of my collar by the wind.
 
I tend to go with the "heat rising" school of thinking for general applications. A good stocking always seems to keep me warmer then say adding another layer. I can keep shorts on by the lake in the evening so long as i have my head covered.
 
mtwarden said:
probably should add this bit as well

"Now, what about hypothermia and heat loss through the head?
If the hypothermia victim is not shivering, they are at rest, and the heat loss through the head remains about 7%. But, this is important, if they are shivering, the percent of heat loss via the scalp can increase to upwards of 55%, so protecting the head well is a very important part of treating the hypothermia patient. And as you can imagine, the primary defense against the cold and hypothermia is vasoconstriction of the peripheral circulation, this shunts blood to the core, reduces circulation to the skin, and increases the percent of heat loss through the scalp."
Click to expand...

Important info here.
 
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