We’re almost three-quarters of the way through what scientists are predicting will be the hottest year on record, so it’s a good time to take a moment to remember those who help keep us cool—air conditioner repair people.

During the 1950s, as AC units were becoming more common sights in U.S. homes, brothers Frank and Harold Mutz were operating a business installing and repairing units. In the 1970s, Frank’s son Thomas took over the business and soon after, Thomas’s son, Frank II, moved to Atlanta and took up the profession as well.

Frank only intended to remain in Atlanta a short time, but working with his father, he found that he had a knack for cooling and heating and ended up staying.

Over the years, their company, Moncrief Heating & Air Conditioning, has grown, and today two of Frank’s three children—Tom and Phil—and his son-in-law, Matt, work alongside him.

Frank and Phil came to StoryCorps in Atlanta to talk about their work; from fixing broken units at churches without AC during Sunday morning sermons, to dealing with cranky customers who need to be turned from unhappy to happy.

Originally aired August 26, 2016, on NPR’s Morning Edition.