Funny what a little exposure does to your perception. Take in the view from a nice wide summit and your radar becomes expansive, your vision sweeping, your sense of the world broad and open. It’s as if you can feel the environment through all your pores, 360 degrees in all directions, absorbing the surroundings like a sponge tossed into water. It’s like outward meditation.

Throw in a little cliff, though, or better yet, a big one, and everything changes. Enter the do not fall zone, the real do not fall zone, and your focus becomes microscopic. Your vision is a tiny little ball a few feet in front of your skis. The slightest sound of the snow under foot screams in your ear. Moving your limbs requires focused concentration, and slightest balance adjustments feel like lurches. It’s as if you only have three sense organs — your eyes, your feet, and a very tightly wound control center.

And the traverse is often the worst. Once you’re skiing, you can fall back on instinct and muscle memory. But sketching along sideways to gravity, that can be the dodgiest, especially when there’s barely enough room for a monoski, let alone a pair of fatties whose legs want to spread out nice and wide and stable. Attention must be paid.

Dave Rosenbarger on the North Face of Aiguille Du Midi, Chamonix, France, by Christian Pondella