It’s dark, and I’m running through waist-deep water, hoping with every rushed step that I don’t fall and twist my ankle. I’m in the Narrows, the slimmest part of the Zion gorge, sharing the chilly river with armies of bugs and a group of guys who assured me they were “prepared.” Of course, I don’t have a headlamp, so I trail closely behind my friend who does. As panicked as I am about breaking a leg, I’m more worried about what will happen if we don’t get back to our shuttle in time. We’d be stranded at the trailhead overnight, 40 minutes by bus from the campground. But we see the headlights as we round the final stretch, jumping on with only seconds to spare and riding back in exhausted silence.

Then there’s the time I summited and descended Mount Charleston in the same day—14 hours, to be exact—also without a headlamp. I wore borrowed hiking boots that made my toenails fall off, and I promised myself I’d never go night-hiking again—until a friend talked me into scrambling to a hot spring in total darkness.

I hate being outdoorsy at night, probably because I’ve done it stupidly and dangerously so many times. But experienced enthusiasts in the Valley mountain bike, boulder and run in the wilds after sundown, including avid night-biker Fran Baker. First and foremost, he says, “Don’t do something you’ve never done before. If you’re going to do a hike for the first time, it’s not recommended you do it at night.” Another tip for rookies is to go under a full moon, when the landscape is illuminated. And remember that day hikes can become night hikes, so always carry a map and compass, first-aid kit, light source, fire-starters, whistle, food and extra layers.

But why is the real question here. People actually like doing this? “It’s sensory deprivation but focus enhancement at the same time,” Baker says of the heightened physicality. “You’re trying to not let your head run away with, ‘There’s someone chasing me.’ I’ve done some night rides by myself, and yeah, on occasion, your brain will do that. There’s a little bit of an extra adrenaline rush in it.”