The information provided should not be used for diagnosing or treating a health problem or disease, and those seeking personal medical advice should consult with a licensed physician. Always seek the advice of your doctor or other qualified health provider regarding a medical condition.

Green springs, warm summers, crunchy autumns and sparkling winters. One of the benefits to living in Wisconsin is that we get to experience the full gamut of seasonal change. But the last on the list often gets a bad rap. Sure, there may be a contingent of people may complain about the heat, but generally speaking, it doesn't stop them in their tracks – just look at the proliferation of the city's street festivals, which don't lack for participation.

However, when we begin our slide into winter in earnest, we may find the call of our cozy beds a little too irresistable.

While a good snuggle under the covers can be desirable from time to time, holing up for half the year may not be the best for your physical or mental health. So before you pull those blankets over your head and wait for the groundhog to indicate your safe return, you may want to take steps to actively re-tune your body to tolerate – and perhaps even enjoy – colder temperatures and take advantage of the associated health benefits through climatization and the magic of brown adipose tissue.

There's just one catch.

More on that shortly, but first let's talk about brown adipose tissue.

Brown adipose tissue (abbreviated BAT, or often referred to as brown fat) is a unique type of tissue that placental mammals – including humans – possess. It's a special fat that converts calories into heat, rather than fuel, and helps regulate body temperature and protect against hypothermia. It is key to a newborn baby's survival, and while BAT is present throughout adulthood, it does have a tendency to disappear with age, especially with disuse.

However, periodic climatization promotes the building and retention of these tissues.

Our body has a variety of features to try to maintain an ideal core temperature, which keeps our internal organs functioning properly. When it gets too hot, you'll start sweating, and your body will also begin to retain more vitamins and electrolytes that are often lost in sweat and urine. Your blood vessels will open up in your extremities to move more blood to the cooler parts of your body (called vasodilation). On the opposite side, when it gets too cold, you'll start shivering, and your blood vessels will constrict (called vasoconstrition) to keep keep more warmth in your body's core (though at the expense of your fingers and toes). You'll also automatically start growing more of that warming brown adipose tissue.

And therein lies the catch: If being cold produces more brown adipose tissue to keep you warm, then the best way to adapt and better tolerate the cold is to just … be cold more often.

You don't have to go to extremes, with periodic icy dips into Lake Michigan, like the Korean pearl divers who continued their work through winter in nothing but cotton swimsuits. But generally speaking, the colder the temps you experience, the more tissue your body will build to keep itself warm.

I should note that too much time in the cold can be dangerous, and none of this is medical advice. Please consult your doctor on the risks, understand your personal limits and use proper clothing and gear before you continue.

The good news is the process of climatization takes a relatively short amount of time – approximately two weeks – and if you take steps to keep active outside as the temperatures drop, you probably won't even notice it's happened. Then, come spring, you'll start to understand why some Wisconsinites are more inclined to wear shorts when the temps crack 40 in March, while Californians run for their parkas when it drops below 60 in October. It's not just perceptually warmer by comparison (though your mental state is key to seasonal enjoyment as well); after winter, our body's furnaces are running at full blast.

Take this anecdote from Paul Ward, a marine biologist in Antarctica:

"We all had our own jobs that often involved getting very cold at some point, in my case it was while fishing in boats or by skidoo through ice...I hated getting fish out of nets as my hands and fingers hurt with the cold, flushing hot, then cold. I never came to actually enjoy this part of the job, but after about a month was able to put up with it and just get on.

"Later that year...the first ship of the season arrived and we winterers were all outside excited to see some new people...While we were wearing cotton t-shirts with our issued long overshirts with sleeves rolled up and untucked at the waist, we were surprised to see those coming off the boats in warm coats, fully done up and with hats and hoods on as well."

And that reveals perhaps one of the most annoying things about climatization: You may not ever enjoy being cold; it will simply make being cold more enjoyable.

Health benefits of cold toleration

With a higher core temperature, your body is less likely to induce extreme vasoconstriction, which protects your fingers and toes from frostbite.

Studies have also shown that increasing your brown adipose tissue can also bring potential health benefits, including weight loss and a lower risk of type 2 diabetes because it burns glucose instead of storing it.

“Upon activation, brown adipose tissue has been related to weight loss and a decrease in body fat mass both due to an increase in energy expenditure, together with increased local and net glucose disposal.”
Obesity Oxidative Stress and Dietary Antioxidants

Additionally, the heat-producing functions of BAT are separate from those that produce energy, so burning calories via winter exercise may be a double whammy, stoking the fires of body temperature regulation on top of burning calories for your chosen activity.

The presence of BAT has also been associated with increased bone density.

And generally speaking, fresh air is good for the mind. With the widespread adoption of indoor ambient atmospheric regulation (that is, heating and air conditioning) we may fall into thermal boredom and miss out on, take for granted or even come to loathe large chunks of our daily life because the temperature falls outside of our narrowed comfort range.

We are winter-folk! Get out and enjoy it.