When the world grows cold, many of us do something supremely stupid. Something that society has trained us to do. Something that amounts to self-sabotage.

The mercury drops and we gradually banish ourselves from the great outdoors, opting to imprison ourselves in the decidedly un-great indoors.

Like a shell-shocked snail, we curl defensively into the comfort of our shell-like homes and the security of our blankets. We begin a kind of waking hibernation. But not the kind that preserves or renews us. Quite the opposite.

Even I, self-proclaimed ardent nature lover, see the trend in my own habits lately. I can’t take the kids to the woods after work because I’m reined in by the early-encroaching darkness. That’s true and unavoidable. But I’m also reluctant to take them outside before work because of the cold morning air, and the hassle of getting them bundled up (even though they rarely complain about temperature). A wintry inertia has started to take hold.

The human body, and the human mind, were not meant to exist indoors for long periods of time. I have believed that fervently ever since I was 20 and I first truly discovered, for myself, the transfixing and transformative wonders of nature.

I spent that summer swimming in one of Minnesota’s 10,000 lakes and exploring the pristine Boundary Waters wilderness. I was working at a canoe outfitter, just a stone’s throw from the Canadian border. (And let me tell you, no one would have gotten hit if I had thrown that stone. Except maybe a loon. This place was desolate.)

For 3 months, I basked in a wide-eyed reverie. I felt like I was seeing — really seeing — the natural world for the very first time. It re-wired my brain and re-calibrated my heart. I think that summer was when I started defaulting to an outdoor mentality rather than an indoor one. And I’d like to think that having experienced that magic, I’ve never gone back.

But I do go back. I do forget this central tenet of my ethos. I do hibernate for days or weeks on end.

And when I do, I pay the price. Anytime I don’t go outside for even 2 days in a row, my body reacts. Something starts to shut down. It’s as if being inside for 48 hours trips a breaker in some biochemical fuse box inside me. My lights go off momentarily. And I have to venture back outside, take a deep breath, and reset my inner circuit breaker.

Underneath our domesticated, carefully curated, climate-controlled civilization, nature is our natural state. Outside the 4 walls that hem us in, we discover the real world. Life itself is out there, hovering in the wild fresh air. A whole universe of un-managed, un-manufactured sights and sounds and textures await us, right outside our front door. A world of wonder and teeming beauty. Even in winter, when living things seem hard to find. And when life itself seems harder to live.

All we have to do is walk out the door.

And breathe deep.