Hiking up to six miles every day isn’t for the faint of heart. Luckily for Chris, he didn’t have one.

“I walked 607 miles with the Total Artificial Heart, so I was really fit going into that surgery,” said Chris, who received his heart transplant after 219 days of support. “That’s very different from a lot of people who go into the transplant really sick. After the surgery, they not only have to recover from the transplant, but also from being sick for so long leading up to it.”

Chris’s heart problems began in 1999, when he was diagnosed with cardiomyopathy, a disease that destroys the heart muscle over time, and ventricular tachycardia, an irregular, fast heartbeat. Although his implanted defibrillator shocked his heart 30 times over a 12-year span, Chris never let his heart condition slow him down. Despite his ejection fraction being only 20%, he continued to hike three to five miles daily and work as a lead instrument technician for ConocoPhilips, which often sent him to the frigid oil fields on the northern tip of Alaska, where it could get as cold as 50 degrees below zero before adding in the wind-chill factor.