what percentage of body heat is lost when not wearing a hat or head covering?

Question

Is it 30 or 70 percntage and where can I get proven study information from?

Answer 1

http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ija/vol6n2/temp.xml

very in depth study 30% is closer to the actual # enjoy the study it was very interesting to read!

Answer 2

You could calculate it based on Planck's equation for radiation of a black body.

To determine the amount of power that is lost, Planck's equation reduces to:

P = A*sigma*epsilon*(T^4 - Ti^4)

Where:
A is the surface area;
sigma is the Stefan-Boltzmann constant (5.67*10^-8 W/m^2K^4)
epsilon is the emissivity (the human body has an emissivity near 1);
T is the temperature of the body (at the point of the skin, about 305 K or 90 F for the average person);
Ti is the temperature of the environment (since its winter, we'll use 32 F or 273 K as this value).

So it would reduce to this equation:

P = A * 5.67*10^-8 * 32

You would need the area of the head to calculate how much heat is being lost for the head itself. Then you'd need to divide this by the amount of total thermal energy (on average) the human body has. Multiply this by 100% and you'd get the value you're looking for.

But on average, the entire human body itself is radiating an average of 95 J/s (or 95 Watts) of heat.

And again, on average, it ends up being about 30%. But...that also depends on the material of the hat and if it covers the entire head.

You could go on and on with this question. The simple answer is: a significant amount unless you wear proper gear for the weather.

You can learn more by googling or reading Physics textbooks on blackbody radiation and infrared radiation.

Answer 3

It seems to be about 30%. The guy with the Stefan Boltzman equation was right!
Rate of Heat loss from surface =A*s*e*(T1^4-T2^4)
Ave rad head =0.1m > A= 4*pi*r^2= 0.126m2
T1= 310K, T2= 273K, assume e=1 and s=5.67x10^-8
> P= 0.162*5.67x10^-8*1*3.68x10^9 J/s =34J/s
Total body heat loss= 100J/s (more over whole bod in cold)
So 30%= right answer! Assuming your bald and beardless!

Answer 4

28.9 % Icelandic study between 1972 -1980, what also was found that keep the head happy and the body follows suit , not to the point of expose the body mind , but fatigue , and well being, a further study is being carried out in greenland at the moment but for hostal planet conditions

Answer 5

Closer to 40% according to OSHA. Most sources cite 30%.

I wonder how much of this is actually exhalation. A lot of heat is lost breathing out warm air and inhaling cold.

Answer 6

you will be able to desire to calculate it according to Planck's equation for radiation of a black physique. to ascertain the quantity of potential it particularly is lost, Planck's equation reduces to: P = A*sigma*epsilon*(T^4 - Ti^4) the place: A is the outdoors section; sigma is the Stefan-Boltzmann consistent (5.sixty seven*10^-8 W/m^2K^4) epsilon is the emissivity (the human physique has an emissivity close to a million); T is the temperature of the physique (on the component of the floor, approximately 305 ok or ninety F for the conventional individual); Ti is the temperature of the ambience (considering the fact that its wintry climate, we will use 32 F or 273 ok as this value). So it could shrink to this equation: P = A * 5.sixty seven*10^-8 * 32 you're able to wish the element of the top to calculate how lots warmth is being lost for the top itself. then you definitely'll might desire to divide this by ability of the quantity of entire thermal potential (on general) the human physique has. Multiply this by ability of one hundred% and you will get the value you're searching for. yet on general, the whole human physique itself is radiating an general of ninety 5 J/s (or ninety 5 Watts) of warmth. And returned, on general, it finally ends up being approximately 30%. yet...that still relies upon on the fabric of the hat and if it covers the whole head. you will be able to desire to pass on and on with this question. the easy answer is: an significant volume till you place on suitable equipment for the climate. you may learn greater by ability of googling or analyzing Physics textbooks on blackbody radiation and infrared radiation.

Answer 7

up to 30%.

Answer 8

30% IT'S DUE TO BLOOD FLOW
The human brain is a great drain on resources, which is why we're omnivours.

numerous studies done, check out sas survival guides.

Answer 9

25%

Answer 10

i thinks its thirty percent goes out through the top of your noggin so wear a hat when its cold