He does heart surgery on gorillas during his spare time:
Frist, at heart, is a doctor. At 5:45 a.m., before a recent Senate workday, he prepared for a quirky slice of surgery. During congressional breaks, Frist, 54, has been known to fly to Africa to operate. But in Washington, he has quietly cultivated another practice: gorillas at the National Zoo.
“These gorillas seem to develop heart disease,” said Frist (R-Tenn.). “It’s totally unknown. I did a lit search — nothing. The fact that we’re working on the edge of the unknown is fun.”