Heilmann was ill for much of the winter after the 1950 season. On March 14, 1951, he collapsed at the Tigers' spring training camp in Lakeland, Florida. He was hospitalized at Morrell Hospital in Lakeland, and the "Detroit Free Press" reported two days later that he was in critical condition with a lung condition. At the end of March, after two weeks in the Lakeland hospital, the Tigers' owner Walter O. Briggs flew Heilmann back to Detroit on his private plane. Heilmann was taken by ambulance from the airport to Henry Ford Hospital, where he remained hospitalized. He remained hospitalized through the month of April, and Ty Tyson was selected to fill in for Heilmann on Tiger broadcasts during Heilmann's illness. Heilmann was released from the hospital and returned home in May 1951. On June 1, 1951, he was greeted warmly by the crowd when he and his wife attended a game at Briggs Stadium. He also returned briefly to the Tiger broadcasts in early June, sharing the duties with Tyson and Paul Williams.