We were taking a break on a rocky outcropping at 13,000 feet when I was hit by a terrible headache. My temples throbbed as my heart pounded in my head. I felt as if my blood vessels would burst.
"Vamos," our guide said. "Time to go."
We were on day two of a three-day trek across the Andes Mountains. We had already ascended 1,000 feet that morning, but had more than twice as far to go until we hit the summit.
I'd spent months preparing for this hike, but no amount of exercise at sea level could help me breathe at that altitude, and all of my "training" seemed naive, absurd. I just couldn't catch my breath.
All around me, other members of the group were taking swigs from their water bottles and zipping up their backpacks, ready to get back on the trail. I sat there with my head in my hands, trying not to panic. What if I physically couldn't go on? Was it too late to turn back? And how mortified would I be to give up, to fail?
As my anxiety increased, so did my heart rate. I had to do something.
I went to our guide. "My head really hurts," I said.
"You'll be okay," he said. "Just take your time and keep breathing."
Keep breathing? I would have laughed if I wasn't on the verge of tears.
But I closed my eyes and tried to marshal all of my yoga Zen to calm my breath, to stop the pounding in my head. And after a moment, it started to work.
"Ready to go?" our guide asked. And to my surprise, I was.
We made it to the summit about three hours later, exhausted but exhilarated and a little delirious from the lack of oxygen. The wind whipped through my hair and clothes, and my eyes filled with tears due to the cold, a powerful sense of triumph, and the beauty of the snow-capped peaks high above us and the valley far below.
And I was so damn happy to be there.
With a Perspective, I'm Lisa Thomson.
Lisa Thomson is a marketer and writer. She lives in Oakland.