Humans are virtually unique among species in altering their environment to better suit their needs. (How much they alter that environment is a matter of some debate, but that doesn’t concern us now.) No other species that we know of has created an artificial means of changing the ambient temperature of an enclosed area. Some animals and plants can regulate their internal temperature, but not that of their surroundings. We’re alone in that.
Heating things up is fairly easy. Fire is one of the oldest inventions of mankind, and it’s practically the standard marker for human habitation. Almost nothing in nature can cause fires—lightning is one of a very few examples—and wildfires are uncontrolled by definition. A tended fire, then, screams for a human interpretation.
Fire, of course, has been useful for many things throughout history. Cooking was one of its earliest uses, with pottery and metalworking coming along later. And as the ages have passed, our command of the flame has only grown. We’ve gone from open fires to furnaces and ovens and incinerators. We’ve changed from using wood to coal to electricity and gas and even lasers.
On the other side of the coin, cooling is much, much harder. Fans are old, but they’re awfully inefficient. Ice melts, and if you don’t have a way to make it, you’ve got to carry it in from elsewhere, losing some (or most) along the way. Some places had the ability to store food in the frozen ground, but that usually only works about two or three months out of the year. It wasn’t until the Scientific Revolution that we starting developing ways to create artificial cold, through vacuum pumps and air compressors. Today, we can reach somewhere around a billionth of a degree above absolute zero, the coldest possible temperature, but the vast majority of our ancestors were virtually out of luck.
Where we stand
So, the state of our magical world is, compared to ours, pretty dire. We’ll start with cooling technology. That’s easy, because there basically isn’t any. Without magic, we’re mostly limited to fans and (when we can find it) ice. Instead of modern air conditioning, houses were built to control the flow of heat. High ceilings allowed hot air to rise, effectively cooling the lower floor. Houses could be constructed to take advantage of the prevailing winds. And food that needed to be preserved could be salted or smoked or pickled. Or kept in cellars, where the temperatures are fairly steady and cool.
As in our world, heat is another matter altogether. Our created world has a good command of fire, even before you add in the arcane. They can work (some) metals, which requires great heat and, more importantly, control of that heat. Houses have hearths and fireplaces, and sometimes ovens. A few public buildings have something similar to the Roman hypocaust, a kind of central heating created by piping hot air underneath a raised floor and behind the building’s walls.
Magic’s helping hands
In fantasy stories, fire is typically the most destructive magical element, as well as the most “flashy”. The fireball is the sword-and-sorcery spell. As usual in this series, however, we’ll eschew the over-the-top explosions and stick to something more low-key, but much more effective in advancing the state of a civilization.
It’s still simple to command fire in our magical world, and it is most certainly given to militaristic and destructive uses, but more peaceful mages have investigated arcane fire for its more beneficial properties. A reliable fire-starter is merely the first of these. Starting a fire in older days tended to be…difficult, but the mages have created a solution. It’s a tiny magical crystal, of the same kind we’ve seen in previous entries, but attuned to fire and heat. Attached to the end of a short stick, it causes tinder to ignite within a few seconds. In modern terms, it’s a lighter.
Larger versions of this produce much more heat, but they’re more expensive and less efficient, making it less than practical to use them for home heating. Mages are working on that problem, however. A few richer individuals can afford the waste, and they do use these fire crystals to heat their homes in the winter. But even their cooks prefer the tried-and-true methods of a proper fire, even if it was started by magic.
Cooling is a harder problem, even for magic. That’s because, technically speaking, there’s no such thing as cold. There’s only the absence of heat. Making something colder requires taking away some of its heat. Fans, for example, work by causing a breeze; the moving air carries away the heat near your body, which has the effect of cooling it. That’s one strategy that can be exploited by magical means, and our mages have done so. Electric fans obviously need electricity, but arcane ones can be powered by the same force providers we’ve already met. Those are expendable—and thus costly—but they get the job done.
Besides these forms of crystallized magic, the wizards of our magical world have a few other tricks up their sleeves. Personal spells, of course, are very important. Mages can light their own fires at the touch of a finger and an arcane word. They can provide their own cooling winds. And some of them can even use spells to increase their own ability to withstand extremes of hot and cold.
Far and wide
But the biggest impact of this greater command of fire is in the knock-on effects it brings to the rest of the world. Starting fires is great, but they’re only useful if you, well, use them, and it’s hard to find medieval-era technology that couldn’t benefit from better ways of making heat.
Metallurgy is the obvious winner here. With magic allowing bigger, hotter, more controllable fires and sources of heat, it becomes possible to melt and boil metals otherwise impervious to the era’s tech. This leads to better, purer alloys, among other things. Steel, naturally, will be one of the first. Historical methods of production were largely limited to small batches until the Industrial Revolution.
Cooking advances with better heat, too. So do many manufacturing professions. And if magical methods of heating become easier and cheaper—this is not a given in our setting, but it could be in others—then wood and charcoal fall out of favor everywhere, because magic takes over. Environmentalists rejoice, because even this modest level of magic means that coal never becomes needed for heat. Nor does oil. The entire fossil fuel industry is obsoleted before it’s even born.
It’s counterintuitive, but better heat technology will also lead to a greater understanding of cold. Most of the early discoveries about cold had to wait until things like steam power and vacuum pumps arrived. Magic short-circuits that, though. Magical means of power generation take the place of steam engines, even in laboratory settings, potentially allowing the science of refrigeration to progress much earlier. Our magical kingdom is on the verge of such discoveries, with all they represent. The first true refrigerators and freezers may be less than a lifetime away. Even if they aren’t, nothing more than an easy way of producing ice is a century or more of advancement.
The next part of this series will move on from heating a house to building it. We’ll see how magic aids in construction, from building materials to architectural designs. For now, since summer has started, find somewhere cold and enjoy the fact that you can.