Myth: We lose most heat through our heads
When it comes to wrapping up on a cold day, a cosy hat is obligatory. After all, didn't your mum tell you that most of your body heat is lost through your head? The face, head and chest are more sensitive to changes in temperature than the rest of the body, making it feel as if covering them up does more to prevent heat loss. But in fact, covering one part of the body has as much effect as covering any other. The hat-wearing advice can be traced back to a US army survival manual from 1970 which strongly recommended covering the head when it is cold, since "40 to 45 percent of body heat" is lost from the head. This has, however, since been disproved.
Myth: Hot, alcoholic drinks like Glühwein keep you warm
Despite the rumours, alcohol is not a good way to stay warm. Alcohol actually lowers the core temperature of your body. The rush of heat that drinkers feel is the warm, fresh blood leaving their core and heading to their extremities. Though you might feel warm in the short term, it will make it harder to stay warm over time, increasing your risk of hypothermia. Just one alcoholic drink will start the process that results in a lowered core body temperature. So that's why you always feel so cold at the Christmas markets.
Fact: Your breath can freeze
You may have noticed that you can see your breath when the weather is cold. When warm, moist breath meets cold air it cools and condenses into water droplets. The cloud of condensed water droplets then mixes with the cold, drier air and usually evaporates. If the air temperature is especially cold, the water droplets can freeze and become ice. That's why at temperatures below -20C events such as cross country ski races have to be cancelled. If cold air reaches the lungs, the lungs may react by releasing histamine - a natural chemical often released by the body during allergic reactions. In people with sensitive airways or asthma this causes wheezing.
Fact: Women feel the cold more than men
True in part. Women tend to have less body mass and muscle than men. Body mass and muscles both produce warmth -- even when you're not doing anything.
Fact: Cold weather can make you sick
True in part. Whilst the cold weather is not responsible for you getting the sniffles and a sore throat -- that's caused by a viral or bacterial infection -- scientists believe that lower temperatures weaken the nose's first line of immune defences. So, the cold weather doesn't cause the infection, but does make it harder for you to fight it off.
A wintry scene in the Valais last January. Photo: The Local
Fact: Car (and phone) batteries can freeze
It takes very cold temperatures (around -25C) for a fully charged car battery to freeze. But if a battery is discharged because of damage to cells, poor connections or a charging system that isn't doing its job, the battery could start freezing at around 0C. If your car battery does freeze it will usually be damaged, and in most cases you'll need to buy a new battery. If possible, it's a good idea to have your battery (or batteries) tested prior to the cold weather snap. And maybe invest in a battery warmer -- a simple sleeve that slides over the battery itself.
Mobile phone batteries can't cope well with the cold either, especially iPhones. So if you're out on the ski slopes don't rely on your phone to get in touch with friends you're planning to meet up with -- arrange a meeting point beforehand.
Myth: A hot bath helps if you're feeling chilly
It's better to have a warm (not hot) bath or shower if you've been out in the cold for a long time. Your veins contract in the cold to prevent losing heat from the centre of your body by pumping too much blood into your extremities. Hot baths decrease blood pressure by opening and relaxing the walls of the blood vessels, but if you've been out in the cold this can lead to a rapid drop in blood pressure, making you feel light headed, faint, or drowsy, which may lead to unconsciousness. Bath water should never exceed 38C, and don't stay in for longer than 20 minutes. Beware of this if visiting one of Switzerland's many thermal baths after a snowshoe walk in the cold!
Fact: Earrings and piercings freeze at sub-zero temperatures
Metal freezes more quickly than skin. So it's best to remove metal earrings and facial piercings when you're doing winter sports - or even going for a walk on colder days. This way you won't get frostbite on your earlobes or nose.
Fact: Air quality worsens during cold weather in cities
Roaring fireplaces, wood stoves and idling vehicles in the winter all add up to higher levels of particulate matter and carbon monoxide. On top of this, cold temperatures and stagnant air create a build-up of these substances near the ground, particularly during a weather phenomenon called temperature inversions. In other seasons or weather conditions, warm air sits near the ground and the air can rise easily and carry away pollutants. In a temperature inversion, cold air is trapped near the ground by a layer of warm air. The warm air acts like a lid, holding these substances down. During a temperature inversion, smoke can't rise and carbon monoxide can reach unhealthy levels.
Plenty of snow in Villars in December 2017. Photo: The Local