The rock was cold enough to numb my fingers. It was October 2, and I was on my eighth and final climbing excursion of the season, before winter set in. All summer, I had gone climbing every time someone with the necessary expertise and gear was willing to take me along. I had tried to systematize my outings, repeating the same routes to see if I could get farther, and stay calmer, each time.

In previous years, I would have pushed myself until my panic was unbearable, hoping that I could pop it like a soap bubble if only I tried hard enough. But now my strategy was to go only as far up as I could without paralysis setting in. The goal was to build up the alternate structure in my brain that said "This is okay. You are safe," then come down before the old structure could assert itself, and hope to get a foot or two farther next time around.

For this last outing, three friends and I were at Copper Cliffs, a crag in Whitehorse's semi-industrial backyard: once a booming copper mining area, now a maze of quarries and mountain biking trails and small, shallow lakes. I was climbing Anna Banana, a short, beginner-friendly, sixteen-foot route up one side of an arête, a sharp wedge of rock protruding from the main cliff face. My first steps had been on easy footholds, gaps cutting into the leading point of the wedge, and I had no trouble until my feet were seven and a half, eight feet off the ground. I stalled out there, my right foot resting on a good ledge just around the corner of the arête while my left toe was tucked into a little cubbyhole a foot below. To continue, I had to pull my left leg up several feet, to the next good hold.

I raised my arms and patted the rock above my head, blindly seeking out handholds that I could use to pull myself up higher, to give my left foot a fighting chance. I tend to trust my hands and arms first, even though my legs are exponentially stronger: We're less accustomed to trusting a narrow toehold than a fist clamped around something solid. But I didn't find what I was looking for, so instead I spread my arms out wide and locked my fingers around the best stabilizing holds I could reach. Then I pushed off with all my weight on my right foot, pulled my arms tight to keep me close to the rock face, and scraped my left foot up the wall until I found the next hold, just as my right toe lost contact with the rock. I balanced there for a moment, then raised my hands to holds suddenly within my reach and pulled up my dangling right foot.

I had done it. More importantly, I had done it calmly and coolly, without needing extra minutes to fight off panic, without groaning and moaning before I gave it a try. My belayer lowered me down so I could climb up and do it again—more confidently, with even less hesitation. This time I kept going, through a series of easy moves to the top of the route, where I reached up and smacked the anchor bolts in triumph: a touchdown spike. I did a quick mental survey of my body: My breathing was steady, my head clear. For today, at least, I had successfully re-directed my brain to reject fear.

Months later, I'm still working on training my brain. I've kept climbing through the winter, at big indoor gyms in San Francisco and Vancouver and on small, homemade climbing walls here at home; in local schools and in a friend's basement. By my standards, I've made substantial progress. These days my chest doesn't constrict and my pulse doesn't start to pound in my ears until I'm much higher off the ground: six, eight, ten feet. Sometimes I can complete an entire short route without feeling afraid at all.

I've started applying the basic ideas behind exposure therapy in other areas of my life, too. So often, whether in our careers or our athletic endeavors or even our love lives, we're encouraged to "take the plunge," to "push our limits," to "go big or go home." But my DIY climbing therapy has taught me the value of care, of caution, of building up your abilities and endurance slowly to reach a larger goal. Taking the plunge has its place, but sometimes it's enough to immerse yourself toe by toe.