An eleventh-hour medical crisis forced Motörhead to call off a highly anticipated festival set last night.

The heavy-metal veterans canceled their appearance at the Monsters of Rock Festival in São Paulo, Brazil after frontman Lemmy Kilmister began suffering from symptoms of gastric distress and dehydration, according to Ultimate Classic Rock. He was taken to a local hospital to undergo tests while his bandmates and Judas Priest reportedly filled the band’s allotted time onstage.

Kilmister, 69, has been stricken by health problems since he was diagnosed with diabetes in 2000; over the past two years, the band has canceled several shows. He was also diagnosed with a hematoma in 2013. “He’s got a really bad diabetic problem and it changes on a daily basis,” Motörhead manager Todd Singerman told Ultimate Classic Rock last year. “A lot of it is fighting the bad habits, the things he’s not supposed to do any more. He’s stopped smoking, but he probably sneaks Jack and Coke here and there — he’d be lying if he said he’d stopped.”

Monsters of Rock continues today with headliners Kiss. Motörhead are currently working on a new album.