Until about a decade ago, my family lived in a large, beautiful, historic home that retained many of its original features. In summer, it was bliss — the thick walls meant we never even needed air conditioning. Winter was a different story. That house was really difficult to heat, in part due to its high ceilings, and no combination of wood fireplaces, oil radiators, and a location-specific type of thermoaccumulative electrical heating that used bricks encased in metal was ever able to consistently keep that house at a comfortable temperature.
The fact that that house was, basically, always freezing cold in winter was a big reason why we moved, in fact. After we settled into a modern apartment with central heating, in the dead of winter, however, I noticed a couple of things. First, I was able to get from the bathroom to the bedroom without shivering, which was nice. We also all, on the other hand, felt constantly fatigued — frankly, exactly the way you might after visiting a sauna. Though we got used to this "first world problem" after a while, it still hits from time to time, especially when it's really cold outside.
Why might excessive heat make you feel tired, and how does this happen in winter time?
The human body depends on a consistent temperature range to function optimally — a range generally defined as lying somewhere between 98 °Fahrenheit (37 °Celsius) and 100 °Fahrenheit (37.8 °Celsius). Dip below that, and you are starting to deal with hypothermia. Stretch beyond it, and you are looking at the opposite; hyperthermia. While your core body temperature is influenced by a range of factors, they certainly include the temperature of the environment.
Of course, your body takes steps to compensate for uncomfortably low or high temperatures as it seeks to maintain equilibrium, or homeostasis. In other words, when your environmental temperature is too high, your body has to work harder to regulate its temperature (called thermoregulation), in this case too cool it down.
Dehydration is one thing that can quickly make you tired when the temperature within your environment is too hot. Sweating is another. Metabolic changes are yet another. Even your blood vessels move closer to the surface of your skin when you are overheating, because this helps your body release the excess warmth. Another very important point is that excessive heat during the night keeps you awake, or at least makes your sleep less restful. This, again, contributes to heat-related fatigue.
You will already have experienced all of this in the middle of the summer, or even during a vigorous exercise session.
What can you do to combat heat-related winter fatigue?
While we hate to say it — because we'd love to give you a novel and science-heavy formula that would immediately improve your life in ways you wouldn't have thought of on your own — there are no surprising answers here. Studies have shown that people tend to be most productive and energetic (the opposite of the tiredness you may be feeling right now) when they're in environments where the temperature goes up to 22 °Celsius (71.6 in Fahrenheit).
Your answer, then, is to reduce your indoor temperature. You can achieve this in a variety of ways:
- Turn the heating down. That thermostat really doesn't need to be that high. If you find yourself feeling cold even when your room is heated way beyond room temperature, it's probably because you're not moving enough or not wearing enough. Try an extra sweater or a quick workout — and not only will your health and comfort increase, but so will the numbers on your utility bill.
- Turn the heating off or way down before you go to sleep. Sleeping in an overheated room is one of the worst sleep hygiene mistakes you can make, and one that will definitely make you tired. Aim for 65 °Fahrenheit (which is 18.3 °Celsius).
- Open the windows. Proper ventilation is extremely important, and opening the windows every day for a significant period of time is one of the best ways to achieve it.
- Keep hydrated. You already know the drill — drink water, not coffee, beer, and the like, to stay well hydrated. Do so before you start to feel thirsty.
The secret to avoiding that overwhelming fatigue caused by winter heat is, it turns out, no secret at all. Turn that thermostat down or reduce the temperature in any way you can — down to healthy levels that your body can tolerate easily.