Aconcagua: 2 steps, 15 breaths near the top

Aconcagua is the highest mountain in South America, 6,961 metres, and the highest anywhere outside the Himalaya. It was my fourth of the seven summits, and the one that taught me what thin air really does.

You measure the climb in breaths. Low on the mountain I walked two steps and took six breaths. Higher up it was two steps and ten. On the wall near the top, two steps and fifteen. On the last stretch to the summit, two steps and twenty, and even that did not feel like enough.

It took about two weeks and one fourteen-hour day. Once the mules turned back at 4,200 metres I carried my own loads, 18 to 24 kilos, up and down between camps until my blood oxygen read 49 percent at high camp, the level where a hospital reaches for a mask.

Near the top a guide kept offering to turn me around. It had the opposite effect. I had a hard cutoff of 3pm and I made the summit at 2:40, dropped my bag, and lay on my back for three minutes just to breathe. The view was fog. The joy was half an hour on a cold rock, sipping tasteless tea, too spent to celebrate.

I lost six kilos up there. I would do it again.

One of the five behind me. Two summits still to go.