It sounds like a joke, but one winter, in Canadian high school, we went up north and learned how to make igloos, or, more precisely, snow shelters. What I remember most about the experience was not the cold but the sleep. Our instructor had taught us to poke a small air hole in the roof, to wear a wool hat (a toque) to bed, and to climb into double sleeping bags. And then, he predicted, the "best sleep you'll ever have."
He was right. After snowshoeing to our snow homes and burrowing in, I remember falling into what must be the deepest state of dreamless sleep humans are capable of. It was the mythical supersleep, deeper than any other, the Atlantis of the unconscious. It was a heavy dose of what scientists call slow-wave sleep. I've been trying to find it again ever since—but the question is, where?
A snow cave was a good place to start. In retrospect, it combines several elements likely to lead to deep sleep. A full day of hard exercise. A firm bed (snow). The sense of being buried under several feet of insulation. And most of all, the cold. As Herman Melville wrote in Moby Dick, "a sleeping apartment should never be furnished with a fire, which is one of the luxurious discomforts of the rich." To find the best sleep, he said, you must "have nothing but the blanket between you and your snugness and the cold of the outer air. Then there you lie like the one warm spark in the heart of an arctic crystal."
Science helps explain what we're looking for in the search for supersleep. Sleep researchers classify sleep into four different stages, including the well-known REM, or "rapid eye movement," stage, and three stages of non-REM sleep. During the night, you cycle down through the stages and back up to REM-sleep, which is actually the closest to being awake. Most writers and scientists seem interested in REM sleep, because that's when Freud-style dreams take place. But a sleep connoisseur seeks something different: the bottom of the cycle, known as "slow-wave," or N3, sleep. Slow-wave is the deepest and most dreamless of sleeps, a form of sleep that makes neurons shut down. How much slow-wave you actually get varies quite a bit. Hence the search for more of it.
In search of big doses of that slow wave, it's worth traveling to some places for the sleep alone—"sleep tourism." With a drowsy fondness I recall Turkey's Capadocia region, where you can rent a room carved out of stone—a cave really—to pass out in. It can make you start to think this whole house thing may have been a big mistake. There is something about lying in a cave that is hard to replicate in an urban apartment or even the suburbs. The Turkish caves form the ultimate bedroom community: darker than night, deliciously cold, with blankets that are thick and beds that are firm. (They are built, after all, on solid limestone.) No wonder cavemen always looked so vigorous.
Another recommendation for the sleep-tourist is the Japanese onsen inn. Imagine a day spent hiking through the Japanese countryside, climbing volcanoes, perhaps communing with the local monkeys. You return, change into Yukata robes, proceed to soak yourself in hot, sulfurous water for an hour or so, then retreat to your tatami room for a lavish meal of duck stew and fish. If, after that, you don't fall into a deep sleep, you might as well give up.
For most people, the American road trip is all about national parks and roadside kitsch, but it can also be a good opportunity for sleeping, if you take it slow. There is something about the wide-open landscape of the West that can lure you into a calm drowsiness. A brisk hike each day, dull stretches of driving, and quiet, empty roadside motels can add up to some good sleep.
In search for supersleep, you should also leave some time for a little variety. Slow-wave sleep may be the prize, the main course, but napping has its own satisfactions as the hors d'oeuvre of the unconscious. You may already have a favorite place, but in my experience, the high temple of napping is the university library. It is a place so good for sleep that it comes close to justifying the whole pursuit of higher education.
Libraries combine several good conditions for sleep—namely boredom, silence, and soft lighting. But what's so rewarding about this kind of sleep is that you typically give into it only after a fight. You've come to the library, ostensibly, to study; perhaps you've a paper to write or test later in the week. But the room is a little too warm, the lights a little too dim. There begins a protracted battle to stay awake. As the head begins to fall, you pick it up and give it a shake, but it does not help. The vision grows blurry. As the head falls onto the page, you may not even be aware of the moment of surrender. The subconscious mind has defeated the ego, and five minutes can feel like five hours. The only problem is waking up in that familiar pool of your own saliva, with arms and legs frozen solid.
The library nap falls into a broader category of sleep that is enjoyable precisely because you are supposed to be awake. Sleeping in the library is a close relative to dozing in the classroom or in front of the television. Instead of trying to get to sleep, you are meant to be awake, and that makes all the difference. It explains why some people seem only capable of their best slumber at the opera.