WHEN IT IS COMPLETED IN 2010, ALMA—the Atacama Large Millimeter Array—will aim 66 radio telescopes at the heavens from a plateau high above the Chilean desert, seeking clues to the origins of our universe. On a recent assignment to South America, I was granted permission to visit this spectacular, well-guarded aerie.

At the ALMA operations offices, 9,500 feet above sea level, a medic led me into a clinic for a few simple tests. These would establish my fitness to drive up to the site, at 16,500 feet, by ruling out a high risk for heart attack or altitude sickness.

The medic slipped a cuff around my arm. I waited calmly as he read the numbers, then watched in disbelief as he shook his head. I’d failed the blood pressure test. I beseeched him to try again. He did—seven times—but to no avail. At 10 points above the diastolic cutoff, I was deemed unfit to ascend.

Adventure travel is my vocation and my passion. I’ve trekked in Tibet, hiked the Inca Trail and mountain biked in Telluride—all at high altitude. When I’m not traveling, my workouts are strenuous. At 53, I consider myself as fit as someone years younger.

The medic listened patiently as I told him all this, but the numbers had spoken. Back down the mountain I went.

That afternoon, over lunch at the Explora resort, I shared the story with my companions. Witnessing my dejection, one of our guides spoke up. Next to the ALMA site, he said, was an extinct volcano called Toco, 18,350 feet high. We could climb Toco tomorrow—and look down on the ALMA site, nearly 2,000 feet below.

It was a risk, and I knew it. According to the numbers, I might well have a heart attack. My father had died that way, the day after his 54th birthday. Although he was my physical opposite — overweight, sedentary and for years a heavy smoker— genetics don’t always play fair. The possibility that I might share his fate now demanded reflection. Should I put my life on the line to thumb my nose at the ALMA authorities?

I didn’t sleep well that night; but sometime before dawn a rush of insight overcame my caution. This wasn’t about ALMA; it was about me. If I didn’t make the climb, my self-confidence would be shattered. I’d see myself as a man with a heart condition, hobbled by fear. That wasn’t how I wanted to live.

Later that morning the Explora van zigzagged up an old mining road along Toco’s flank and deposited us at the trailhead: a clearing at 17,000 feet. One step after another, we made our way upward. The air was so thin it was like breathing through a straw. At least 20 times I stopped, gasping, listening to my heart race.

It was a giddy moment when the cairns marking the summit came into view. We hugged each other and celebrated with brownies and coca tea. Far below lay the borders of Argentina and Bolivia—and ALMA. “Did you know,” my guide asked, “that alma means ‘soul’ in Spanish?”

It made perfect sense. Gazing down from Toco’s summit, I searched my soul and vowed to make lasting changes: to spare the salt, cut back on caffeine and see my doctor every three months. The sphygmomanometer numbers were not a death sentence, but they were fair warning. I could choose to ignore them—but if places like this were my passion, I’d better take them seriously.


First Person originates at the other end of the stethoscope, presenting essays and commentary from patients, consumers and other medical outsiders. Proto invites your contributions; please send ideas to the editor.