The American Lung Association's Fight for Air Climb takes place in cities around the country, but Milwaukee is home to the nation's largest climb.
People like Rosanna Balistreri climbed 1,034 steps to the top of the U.S. Bank building to raise money to fight lung disease and breathing issues.
"I recruited my three daughters this year, and my sister," Balistreri said.
She climbs for her mother who died from lung cancer three years ago.
At first, Balistreri didn't think she could make the 47 floors to the top. She said the people around her changed her mind.
"There's so many people who are in there saying, 'You can do it! See you at the next level. You can do it!'," she said.
Volunteers cheered for the climbers along the way and help them stretch before and after.
Some of the participants take the climb a step further and do the Ultimate Climb. They climb the 1,034 steps as many times as they can in one hour.
Two people who spoke to TODAY'S TMJ4 made the trip five times in 60 minutes.
"Could have done a sixth but we ran out of time," one of the ultimate climbers said.
TODAY'S TMJ4 sponsors the Fight for Air Climb in honor of our late news photojournalist Michael Greene who died from lung cancer three years ago.