interesting

[demented dale]

Scientists debunk myth that most heat is lost through head

Popular beliefs – including hot heads, kids high on sugar, and eating in the evening making you fat – have been blown out of the water

www.theguardian.com

 

[demented dale]

Scientists debunk myth that most heat is lost through head

Popular beliefs – including hot heads, kids high on sugar, and eating in the evening making you fat – have been blown out of the water

www.theguardian.com

looks like that is loaded now, x

 

[C_Claycomb]

And that is 5 minutes I will never get back. As articles about science go, that was pretty poor journalism of what sounds like poor science, and amounted to saying “scientists looked at common beliefs, then looked for proofs in other papers, and say the beliefs are false”. Seems like an easy way to publish a paper without needing to do any experiments oneself….and publish an article without doing research.

One of the “myths” the “scientist” claim to bust is that children’s behaviour is effected by consuming sugar. Having witnessed the behaviour of groups of children pre lunch and post lunch (inc a huge marshmallow each), I call BS on the scientists claiming it’s a myth.

As for the heat loss through the head thing. I think their “myth bust” gotcha is more a sleight of hand to get published than useful to outdoors folk. Saying that when out in cold weather you lose 40%of heat through your head and should wear a hat is useful and practical. People usually wear clothes, but not always head gear. Disagreeing by saying “but if you were outside in cold weather in just your underwear, a hat wouldn’t stop 40% of your heat loss” is not useful or practical and sounds like “science” by a contract lawyer.

 

[Pattree]

Just a newspaper selling copies.

 

[TLM]

Hmm ... I think C_C is correct based on my own extremely subjective observations.

On the heat loss thing I think "The scientists" are just bad readers or don't understand. US army has no interest in studying heat loss on naked soldiers but lots in studying properly dressed ones. My first guess is that the whole point was studying how to diminish heat loss of dressed soldiers and there head becomes important though breathing might give that a race when activity level is high. (I just read a Canadian study that strongly suggested the use of breath heat exchangers in winter time.

 

[The Frightful]

Ive got plenty of hair and wearing a hat certainly makes a big difference to my overall temp, its the first thing to come off when i get uncomfortably hot. Surely percentages are meaningless, general body mass, skull bone density we're all different....if the cap fits......

 

[Herman30]

For me, if I run hot wintertime, it is often enough to open up around the throat and neck. A cool breeze there when one is sweatty feels very refreshing.
And since I lack hair on top of my head it can feel very cold without headwear.

 

[Pattree]

I remember the days when newspapers reported events and news stories on their first few pages. “Opinion”and “Interest” stories appeared in clearly labelled columns somewhere after five and eight pages.
Now even the front page headlines are biased opinion.
The job isn’t to inform any more, it’s to sell newspapers using the equivalent of the internet sound bites.

When we had a coal fired heating system it was worth buying our local evening paper. Now we burn oil and we’ve cancelled it.

We haven’t had a national paper for more than fifty years. The OP is in part why.

Broadsheets like The Telegraph or The Guardian aim for reading scores of 70 to 90, so are readable by 12–13 year olds

 

[demented dale]

Scientists debunk myth that most heat is lost through head

Popular beliefs – including hot heads, kids high on sugar, and eating in the evening making you fat – have been blown out of the water

www.theguardian.com

I just said it was interesting. I know better than hold an opinion these days. x

 

[demented dale]

I just said it was interesting. I know better than hold an opinion these days. x

I followed this up with a search question. It is not only this article that says it. There are many sources, including the US military, claiming the same. Again, interesting.

 

[Pattree]

Nowt wrong with an opinion here on BcUK Dale. Few of us are claiming any authority other than experience.
There is a sort of floating “In my opinion” over every post.
National newspapers however claim some sort of accuracy in their reporting.

It’s pretty easy to “debunk” an idea that not many of us held or cared about. Doesn’t take much editorial effort and doesn’t affect what the reader does.
Parents know about the effect of sugar, I don’t often wear a hat. A newspaper is the last place I’d look for advice on the subjects.

Abstract opinions now? - I’ve a tonne of them. They are very occasionally appropriate but mostly boring. That doesn’t stop me. I’m very good at being wrong!

 

[Dan00001]

I haven't read the article but this is not something new. A study conducted found that heat loss is roughly proportionate to surface area. iirc, you're head represented roughly 7% of your bodies surface area with heat losses about 10%.

I think when the army conducted tests a long time ago, they conducted tests on people full clothed and that's how they came to their 45% or whatever it was.

 

[Dan00001]

The old saying 'if your hands and feet are cold, put a hat on' is still true because your body will prioritise your bodies core organs and brain over it's extremities. You can survive the loss of a few fingers or toes, the same can't be said about our brain. If our hypothalamus, which controls essential body functions such as body temperature, senses that your core or brain is below optimum temperature, it will restrict blood flow to the extremities, such as hands and feet, through vasoconstriction. It can also cool body temperature through increased blood flow to the extremities (vasodilation). So, if your head is cold, so will your hands and feet be, and by putting a hat on to keep your head warm, your body will increase blood flow to hands and feet.

Here is one study on heat loss through the body and head:

https://journals.physiology.org/doi/full/10.1152/japplphysiol.01241.2005

 

[HillBill]

The old saying 'if your hands and feet are cold, put a hat on' is still true

I was just about to say similar until i read your post. It was something we were taught in the Air Cadets and i know to be true.

 

[Toddy]

When hominids stood upright, striding (obligate) bipedalism as against arboreal (facultative) bipedalism, and walked the savannah's, etc., their skulls were exposed to the sun, and it's heat.
Hominids developed a heat dispersing venous system.....
"Hyperthermal species have a special disposition of veins and arteries that allows their brains to remain at a temperature lower than that of the overheated body ..."
We have hair, we have a lot of sweat glands in our scalps, etc.,

Now shift that to our colder regions....and we often feel the cold in our heads and faces, and find hats and scarves, balaclavas and the like to be not just comfortable, but very good things indeed. We still have that tropical suitable venous network in our skulls....the one meant to disperse heat and keep our brains from boiling in the skull.

I'm struggling to find easy access links to this stuff, it's mostly hidden in academic sites, from palaeontology to archaeology.

Inadequate heat release from the human brain during prolonged exercise with hyperthermia - PMC

Brain temperature appears to be an important factor affecting motor activity, but it is not known to what extent brain temperature increases during prolonged exercise in humans. Cerebral heat exchange was therefore evaluated in seven males during ...

pmc.ncbi.nlm.nih.gov

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/bipedalism

Sorry, kind of rambling here

 

[demented dale]

The old saying 'if your hands and feet are cold, put a hat on' is still true because your body will prioritise your bodies core organs and brain over it's extremities. You can survive the loss of a few fingers or toes, the same can't be said about our brain. If our hypothalamus, which controls essential body functions such as body temperature, senses that your core or brain is below optimum temperature, it will restrict blood flow to the extremities, such as hands and feet, through vasoconstriction. It can also cool body temperature through increased blood flow to the extremities (vasodilation). So, if your head is cold, so will your hands and feet be, and by putting a hat on to keep your head warm, your body will increase blood flow to hands and feet.

Here is one study on heat loss through the body and head:

https://journals.physiology.org/doi/full/10.1152/japplphysiol.01241.2005

Thats interesting but what I am reading is that heat is lost from the body at the same rate all over and not significantly more through the head. if we were naked we would lose the same amount from the leg as the head. That one thing contradicts everything I have believed to be true all my life. x

 

[demented dale]

Nowt wrong with an opinion here on BcUK Dale. Few of us are claiming any authority other than experience.
There is a sort of floating “In my opinion” over every post.
National newspapers however claim some sort of accuracy in their reporting.

It’s pretty easy to “debunk” an idea that not many of us held or cared about. Doesn’t take much editorial effort and doesn’t affect what the reader does.
Parents know about the effect of sugar, I don’t often wear a hat. A newspaper is the last place I’d look for advice on the subjects.

Abstract opinions now? - I’ve a tonne of them. They are very occasionally appropriate but mostly boring. That doesn’t stop me. I’m very good at being wrong!

I agree but I then followed it up and found several other sources which all arrived at the same conclusion. The simple point being expressed was that the body loses heat all over equally and not significantly higher through the head which is what I have been led to believe all these years. I love it when what I think I know is challenged or disproved. x

 

[Dan00001]

Thats interesting but what I am reading is that heat is lost from the body at the same rate all over and not significantly more through the head. if we were naked we would lose the same amount from the leg as the head. That one thing contradicts everything I have believed to be true all my life. x

Yes, that is correct, and imo, logical. If I were to walk around with no trousers wearing a woolly hat, I'm pretty sure that I would be more cold.

The studies concluded that heat loss is roughly proportionate to surface area i.e your head at ~7% of your bodies surface area loses ~10% of heat.

 

[demented dale]

Yes, that is correct, and imo, logical. If I were to walk around with no trousers wearing a woolly hat, I'm pretty sure that I would be more cold.

The studies concluded that heat loss is roughly proportionate to surface area i.e your head at ~7% of your bodies surface area loses ~10% of heat.

yep. I always thought that a person lost way more heat through their head. Hot air rises was what I thought. Turns out that according to the studies that is simply not the case x

 

[HillBill]

Thats interesting but what I am reading is that heat is lost from the body at the same rate all over and not significantly more through the head. if we were naked we would lose the same amount from the leg as the head. That one thing contradicts everything I have believed to be true all my life. x

That doesn't apply when wearing clothing, which insulates and traps heat. Prevent the majority from escaping. Heat rises, and blood flows. If you have no insulation on your head, then that would be a primary source of heat loss. You can warm your hands up by putting a hat on, but you can't warm your head up by putting gloves on.