By Dona Suri
The weatherman says we are in for several more days of strong winds, which might not be so bad but it’s a cold wind too. The weather might even turn windy, cold and wet. Brrrrr !
No sensible person will venture out without zipping up their jacket and pulling a warm, woolly cap down over their ears. But just try telling that to kids. No matter how foul the weather, T-shirt clad little chests are bared to the elements. The average kid won’t be caught dead wearing a cap. As for a muffler? What’s that?
Grandma (who walked to school through the blizzard of ’56) would be appalled. Particularly, the scornful disregard for caps. “Don’t you know that the body loses 80 percent of its heat through the head !”
Most of us have heard this admonition so often that we absolutely believe it. But is it true?
Here’s what medical research has to say about heads and heat loss:
Here’s what medical research has to say about heads and heat loss:
* The head only represents about 10 percent of the body’s total surface area. If the head were to lose even 75 percent of the body’s heat, it would have to lose about 40 times as much heat per square inch as every other part of your body.
* In actual fact, whether you expose the arms, legs, torso or head, the rate of heat loss is the same.
* It is true that the face, head and chest are more sensitive to changes in temperature than the rest of the body, so if these parts are exposed to cold air, one has a stronger sensation of cold than if arms or legs are exposed. But, in fact, covering one part of the body has as much effect as covering any other.
So how much heat is lost through the head?
* Heat loss is exactly the same as the surface area: 10 percent.
* The body does it’s best to keep core body temperature constant.
If necessary, it does this by down-regulating blood circulation (and consequently heat exchange) in the periphery (arms, legs). However, the blood circulation through the head (in particular, the brain) stays almost constant which means that heat exchange remains constant too.
If you are outside in cold weather and fully clothed – including a hat – the body will be able to conserve heat all over. If you are outside, wearing a hat, muffler, jacket, gloves … but no pants, then the body is going to lose heat from your feet, legs and bottom.
So, the parental admonition about wearing a cap holds good. Caps don’t do more than their share of the whole job, but the amount of warmth they keep in is still a good thing. Wear a cap. And that’s not all …
* Don’t go out without a warm jacket and zip it up!
* Full pants, please. Winter is no time to be running around in shorts
* Nice woolly socks are essential. Even in the house, don’t pad around without your slippers.
* Dress warmly all over so that the heat generated by the body is conserved.
Aside from avoiding the unpleasant feeling of being cold, it’s important to dress warming during winter so that we don’t catch cold. Right? At least that’s what most of us think. After all, why would a cold be called a cold if weren’t caused by getting cold?
Surprise. There is some controversy over the relation of colds (sniff, sniff, achooo! ) and cold (shiver, shiver, brrrr ! ).
That common ailment, featuring running nose, snotty nose, sneezes and cough, is NOT caused by going outside in low temperatures; coming down with a cold is the result of a rhinovirus getting into your body and multiplying. If you succeed in evading the virus, or your immune system destroys it before it gets a chance to take hold, then you will not get a cold.
But could being exposed to low temperatures make you more susceptible to a cold?
Here are some theories:
* Cold temperature causes blood vessels in the nose and throat constrict, meaning that fewer infection-fighting white blood cells reach your nose and throat to tackle the virus.
* The causative factor is not cold temperature, but sheltering from cold temperature. When it is cold, more people are indoors and in close proximity, so a rhinovirus gets passed around more easily. Warm temperature with low humidity (typical of a centrally heated house in winter) is ideal for spreading a virus.
Going out and getting chilled won’t give you a cold, but if you have already picked up a rhinovirus, then your body might find it harder to fight it.
Bottom line: Science may not entirely support your mom’s edicts vis a vis losing body heat and catching cold, but do what she says anyway.
* When it’s cold outside, dress warm – head to toe.
* Avoid rhinovirus (and every other kind of virus) not by shunning the out-of-doors, but by wearing a mask when you’re going to be near lots of other people. And frequently wash your hands with soap and warm water, too.