He did it less than two years after surviving a dangerous heart condition.
Dr. Robert Gillio was out cross country skiing along the lakefront Sunday.
Last week, he and a climbing partner made it to the top of Mt. Kilimanjaro, the highest peak in Africa.
It was part of an effort to raise awareness about heart disease and to educate young people about making heart-healthy dietary choices.
"The top, it's tough, you know you have heart disease and even if you don't, you feel weak. It feels like you just want to go to sleep, and so keeping the focus is very important," Gillio said.
Gillio still has family in Chicago. He now practices medicine in Pennsylvania.
Check out myclimb.org to read more about people with heart disease who attempt to climb Mt. Kilimanjaro.