Urban legend: most of your body heat is not lost through your head. Photo: iStockphoto
If we were all stuck naked in the freezing cold, the warmest among us would probably be a hairy, well-fed and tubby young man.
There are reasons some feel the cold more or less than others and it's largely down to a mix of our shape, size, age and gender.
According to University of Western Sydney's Professor of Integrative Physiology, Vaughan Macefield, the lean and slender will feel the winter weather more because they have less fat to contain heat escaping through the skin.
Skipping meals or a very poor diet could also create a case of the chills because the body can run out of energy to maintain its core temperature of about 37 degrees.
"We're mammals and we have to consume a lot of food just to keep our body temperature up. If you consider a reptile, cold-blooded reptiles, they don't need to eat as much as mammals. The primary fuel for us is carbs and if you're not maintaining your fuel intake, then your body temperature may well go down," Professor Macefield said.
A very hairy person might have a sliver of an advantage when it comes to coping with the cold but probably not enough to make it worth modelling yourself on Cousin Itt. If the body gets too cold, as in cases of anorexia, it can produce thick hair on the arms and legs to try to trap the heat.
Professor Macefield said our bodies are coldest between 3am and 6am, and warmest from 3pm to 6pm. A woman can also boast of having a body temperature that's half a degree higher than normal when she's in the middle of her menstrual cycle. But that's probably cold comfort for women who are more likely to feel the cold than their male counterparts because they have thinner limbs and less mass.
But it seems the oft-repeated advice that donning a beanie will keep you warmer, because the head is where you lose all of your body heat, is just an urban legend.
The myth comes from a US army study from the 1950s that was performed on people in Arctic conditions, completely covered in clothing, apart from their head or face, Sydney University thermal physiologist Doctor Ollie Jay said.
"Under that particular scenario you're losing so little heat, the majority of the heat will be coming from the head. If you were out in a cold environment, wearing shorts and a T-shirt, it would be absurd to say 90 per cent was being lost through your head," Doctor Jay said.
If you're really desperate to come out of the cold, sprinkling some chilli on your soup will trick your body into thinking it's hot.
The chemicals in the peppers fool the thermo-receptive nerve fibres in the skin and give rise to a sensation of heat without actually increasing your body temperature, UNSW physiology professor Gary Housley said.
While exercising will definitely get you hot under the collar, boosting your temperature by about one degree every 10 minutes, don't rely on muscle to keep you warm at night.
"If you keep moving then your muscle generates a lot of heat and so you will feel warmer but if muscle is just sitting there then it's not actually going to produce much heat," Professor Housley said.