But by 1 a.m. Monday, the 47-year-old rocker and contestant on The Celebrity Apprentice had to be rushed to the hospital with what he thought was a severe case of the flu. Instead, he underwent an emergency appendectomy.
Michaels "remains in the hospital, is doing well and beginning the recovery process," his rep says.
"Michaels, who has been known to perform under extreme conditions that would make most performers cancel, will unfortunately have no choice but to reschedule some of his April tour dates," the rep adds.
The former Poison frontman who went on to become a reality star on VH1's Rock of Love is no stranger to medical woes. A diabetic, he's been frequently hospitalized, gives himself insulin shots and checks his blood sugar four to six times a day.
He also suffered injuries, including a broken nose, when he was hit by a set piece during the 2009 Tony Awards.