(Apologies; once again I neglected to correct for the BVC site rebuild by reposting the essay here. That shouldn’t be an issue for much longer, though!)

I am infamous among friends and family for how easily I get cold. But I maintain that this is only natural: at temperatures below about sixty degrees Fahrenheit (fifteen degrees Celsius, for those of you on that system), human beings can die of hypothermia.

Of course, we’ve created any number of ways to shore up our weakness in that regard. Though we’ve shed most of our body hair, we’ve replaced it with clothing, from furs to wool to high-tech thermal fabrics. We’ve built enclosed structures to keep the rain off our heads and shelter ourselves from the wind, whose interiors can be warmed more easily. We’ve mastered the use of fire. All of these are what my anthropology professors called “cultural solutions”: ways to protect our fragile, heat-loving bodies, evolved for the plains of East Africa, against the very large percentage of the planet that would kill us with cold.

I won’t go into a great deal of detail about clothing because that’s not only a topic we’ve discussed before, but it’s one many of my readers are already familiar with — if not from personal experience of living in a cold region, then at least from having seen movies and TV where characters have to bundle up. Coats, hats, gloves, scarves; you know the drill. And of course we’re familiar with the idea of using fire to warm a space, whether that’s directly with logs crackling in a hearth, or indirectly with a furnace heating air or water which are then piped elsewhere in the building.

But some forms of that heating are less well-known in the modern West. For example, back when we discussed sleeping I mentioned the Chinese kang or “bed-stove,” which draws the hot exhaust from a fireplace through the base of a brick, clay, or concrete platform. This warms the platform, and therefore anyone sitting or sleeping on top of it. Russians have a similar concept, and in Japanese houses you can still find kotatsu, low tables covering a brazier (nowadays usually electric), with a large blanket or futon to drape over the laps of people sitting along the sides.

You can extend this idea either vertically or horizontally. Vertically, it’s a masonry heater: a giant pillar whose material will first absorb and then slowly radiate heat from a fire at the base into the rest of the room. (Because of how it projects into the room, it’s more effective at this than a chimney set flat into a wall.) These seem to be especially common in northern and eastern Europe. Horizontally, you have the Korean ondol or the Roman hypocaust: the floor of a whole room is raised a small distance, and hot air circulates underneath. The latter sometimes even included pipes to raise the heat through the walls and into upper floors, for a very toasty result. Heated floors exist in the modern world, too, and I’ll admit I’m sometimes tempted by the prospect.

All of this works better if you build the whole structure with an eye toward insulation. After all, it does little good to heat your floor if all that nice warmth is just going to dissipate outside! Thick walls can help with this; heck, one of the reasons early humans inhabited caves was because the temperature inside them tended to be fairly stable (albeit not very warm). It also helps to have a buffer zone, whether that’s an “airlock” entry room that keeps winter winds from blowing straight inside, or spaces between inner and outer walls — though far better if that space is filled with something insulating. Asbestos works great! . . . except for the part where it causes all kinds of health problems, and these days you have to hire a hazmat team to remove it if you find it in a building. At Bletchley Park during World War II, the codebreakers stuffed the walls with all kinds of sensitive documents that should have been destroyed, thus providing themselves some much-needed warmth and later historians a gold mine of information.

But one of the most effective moves is simply to limit the area you have to heat, and how many places that heat can escape. Windowless rooms, while noisome in many other respects, make sense when you think about trying not to freeze. Standing screens have been used in many parts of the world to create sheltered pockets within a larger room, and to reflect the heat of a fire back into that space. Big, open rooms are a sign of wealth not only because of the architectural expense, but because making them habitable can be a real challenge.

We’re especially vulnerable to the cold when we sleep. During the day, we get some assistance from the sun, and both eating and moving about help you stay warmer. But lie down in the darkness and go some hours without food . . .

Solutions for this danger go well beyond thick blankets, and I’ve mentioned many of them before, but we’ll recap briefly here. You can place warming items between the sheets to warm the bed itself; these might be heated stones or bricks wrapped in fabric, metal pans filled with coals or hot sand, or rubber bottles filled with hot water. You can have someone else in the bed with you — including animals! English has the idiom “three dog night” to describe a night so cold you need three dogs to keep you from freezing. And while these usually wouldn’t be in the bed, peasants might need to bring their livestock indoors during the winter, putting survival above sanitation.

The “enclosure” idea applies to sleep, too. Bed curtains or box beds mean you only have to warm the air inside, not the whole room. The latter are literally wooden boxes whose doors you close: very practical, but (like windowless rooms) very prone to becoming noisome if the bedding and the interior aren’t regularly cleaned. Of course, while your sleeping area may be nice and warm, you’re likely to get a real shock when you exit in the morning, or if you have to get up to relieve yourself in the night.

Actively heating your living spaces requires fuel, throwing us right back to the issues raised in the first essay for this month, and to our energy problems today. The architectural blog McMansion Hell (run by Kate Wagner, whom I’ve mentioned before) has torn into the modern craze for things like two-story entry halls or living rooms with enormous plate-glass windows: while they may look nice, they’re horrifically energy-inefficient when it comes to heating and cooling. Structural solutions like good (non-asbestos) insulation, double-paned windows, and small rooms that can be regulated individually as needed give a much more lasting benefit. Even for those of us who aren’t ancient peasants living on the edge of subsistence, it makes sense to put thought into how to stay warm without being wasteful.