Slipknot expend a lot of energy onstage, and earlier this summer it got the better of singer Corey Taylor, who passed out from heat exhaustion at the end of their performance.

Taylor tells Fuse that he’s still not exactly sure what happened. He explains, “I basically blacked out for the last two songs, but I finished the show. I have no memory of the last two songs. I woke up backstage with an oxygen mask on and Chris Fehn [drummer] taking my shoes off—which is very weird—and my wife making sure I was okay. And I immediately started freaking out, thinking, ‘Oh my God, we had to cut the show short.’ And she was like, ‘No, you finished it.’ And I was like, ‘Excuse me, I did what?’ That’s terrifying in a weird way. It makes me go back and think, ‘How many other shows have I finished where I have no idea what happened?’”

The singer says that there may have been several factors that contributed to his fainting spell. Taylor says, “It was really hot to begin with but because we use so much fire and we’re in these buildings that are shaped so the heat doesn’t dissipate, it all really builds up. And because we’re firing off propane, it eats up a lot of the oxygen on the stage. This is all what I’ve put together.”

Taylor made it through the rest of the Mayhem Festival without incident and is now preparing for Slipknot’s own hosted Knotfest events.

Watch Corey Taylor Talking About Passing Out on Stage in Dallas