Only about 60 people have completed this challenge. What exactly does it involve?

Climbing the Seven Summits [the highest peak on each continent] and skiing across the North and South Poles. You’re on cross-country skis, but you’re not really skiing. You’re walking with a sled carrying your fuel and food.

You had a brain tumor removed as a teenager, and you’re doing this to raise money for Ann & Robert H. Lurie Children’s Hospital. How did you connect that with climbing?

I went on a safari in 2015 and fell in love with Kilimanjaro. I was not an athlete, but I wanted to climb that mountain. When I did, it became, What else can I do? People who do the Seven Summits get a fair amount of attention. So then it was, What do I want to bring this attention to?

I hear January’s polar vortex gave you the chance to test some gear.

I’d rather figure it out here, as opposed to when I’m on Everest. It’s going to feel cold there because of the altitude. But in terms of actual temperature and wind, Chicago is probably worse than on any reasonable summit day.

What was your coldest climb?

Mount Vinson in Antarctica. We got stuck in our tent for three, four days because it was negative 60 degrees — like, instant frostbite conditions.

My God, how did you pee?

In a bottle.

You had a close call while training last summer on Snowmass Mountain in Colorado. What happened?

The rock I was holding on to broke off, and my leg plunged two or three feet. I’d never seen so much blood. I managed to stop the bleeding, but I had no cell service. I was pretty sure I was not going to make it. I recorded some videos for my family, and I lost consciousness. I came to 20 minutes later and started crawling. After 150 feet, I got one bar on my phone. I called 911, and they put me in touch with Aspen Mountain Rescue, who called the High-Altitude Army National Guard, who sent a Black Hawk helicopter to pick me up. After surgery, I asked, “Can I do my climb in six weeks?” The doctor said, “Probably not.” I hit my rehab hard, and six weeks later, I climbed Cho Oyu, the sixth-highest mountain in the world.

After Everest, what’s next?

I’ll go straight to Denali. Climbing it didn’t work out the first time. We had a very limited summit window, and the weather shut down the mountain. Even people who climb Everest would say Denali is more physical. Each person has to pull a sled with over 130 pounds of gear.

I’m trying to imagine pulling a sled up a mountain.

Oh, you think that’s hard? Try going down.