“Don’t go out in cold weather with wet hair or you’ll catch a cold!”
As AccuWeather reports, many people have heard this sentiment throughout their lifetimes from well-meaning parents or grandparents. Many have passed the advice along to their own children. But just how true are these cold weather warnings?
“I call these ‘everybody knows statements,'” Dr. Gordon Giesbrecht, a thermophysiologist at the University of Manitoba in Canada, told AccuWeather. “Everybody knows such-and-such … The problem with ‘everybody knows statements’ — also known as lies my mother told me or urban myths or whatever — is sometimes there’s some aspect of truth, but it’s been overblown.”
Giesbrecht is one of the world’s foremost experts on cold, which has earned him the nickname “Professor Popsicle.” The “Professor” says that he’s very familiar with the following five weather myths.
You lose most of your body heat through your head
According to The Guardian, scientists have traced this top cold-weather myth to a United States Army manual from the 1970s recommending a hat in the cold because “40 to 45 percent of body heat” is lost from the head.
The Guardian notes the myth became popular as a result of a “vaguely scientific” experiment by the U.S. military in the 1950s. “In those studies, volunteers were dressed in Arctic survival suits and exposed to bitterly cold conditions. Because it was the only part of their bodies left uncovered, most of their heat was lost through their heads,” The Guardian reported.
While the head and chest are more sensitive to temperature changes than the rest of the body, it can feel like covering them up does more to prevent heat loss. However, as Giesbrecht notes, covering one part of the body has as much effect as covering any other, it’s simply about the amount of surface area that is exposed to the cold.
At most, according to a 2008 report in BMJ, a person loses 7 percent to 10 percent of body heat through the head. If your body is bundled up and you aren’t wearing a hat, you’ll lose up to 10 percent of your body heat through your head. If another part of your body is exposed to the cold, you’ll lose a percentage of heat depending on how much is exposed.
As The Guardian reported, “If the experiment had been performed with people wearing only swimming trunks, they would have lost no more than 10% of their body heat through their heads.”
“You’re not going to become hypothermic through your head. But, on the other hand — I’ve got a pretty scientific view of this — if your head is cold, put a hat on,” laughs Giesbrecht.
Being exposed to cold weather can cause the common cold
Bacteria and viruses, not the weather, cause infections such as the common cold, influenza (the flu) or pneumonia.
So why does it seem like so many of us get sick in the winter months? While it isn’t the temperature itself that causes illness, the cold causes more people to stay inside which is associated with an increased risk of catching a virus. Additionally, school is in session during the colder seasons, which can lead to increased bacteria spread among people.
Additionally, lower humidity in colder months may increase the risk of getting certain infections because many common cold-causing viruses arebelievedto survive better in low-humidity environments. There’s also evidence, according to research from Harvard University Medical School, that exposure to low temperatures suppresses the immune system, so the opportunities for infection increase.
A hot drink is a great way to warm up
It may help you psychologically beat the low temperatures, but a hot drink can physically cause your body to cool down faster than a cold drink.
There are nerve receptors on your tongue and thermoreceptors in your throat that cause your body to increase sweating. The output of sweat when you drink a hot beverage is greater than the internal heat gain and when that sweat evaporates, your body cools down. And consuming beverages that are too hot — above 140 degrees — may pose its own set of risks, one recent study showed.
Shivering is a sign that your body is getting colder
Not exactly, Giesbrecht said. Shivering is a defense mechanism against falling body temperatures. When your body does become too cold, its automatic response is to tighten and relax the muscles in rapid, rhythmic succession in order to warm up. Giesbrecht says shivering is perfectly natural, up to a point. Shivering can also be a sign that your body is fighting off an illness, infection or another health problem, so if you have other symptoms, such as a fever, you’ll need to address those issues immediately.
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