The pair were walking off the stage at the end of their final show at Detroit's Comerica Park when Eminem's hype man Denaun Porter reminded the rapper that he had agreed to pour a bucket of ice over his head to raise awareness and funds for ALS research.
"I knew this shit was coming, but—tonight?" Eminem asked, before sitting down in a chair while Rihanna did the bucket-dumping honors. Eminem in turn nominated Porter, producer Rick Rubin and Rihanna, who initially expressed some reluctance to submit. "Detroit, what you think?" she asked the audience. "Should I do it? I'm from the islands; I don't do this ice shit! This ice shit doesn't work for me." In the end, of course, she did accept.
With the concert-closing dousing, Eminem and Rihanna joined the ever-expanding ranks of celebrities spreading the word about the neurodegenerative disease Amyotrophic lateral sclerosis (also known as Lou Gehrig's disease). While the ALS Association's rules for the challenge require either getting a bucket of ice water dumped on your head or making a donation, many appear to be doing both, and the organization has so far raised $42 million, according to NBC. Other recent initiates include Justin Bieber, Arcade Fire, the Foo Fighters, Taylor Swift and Chris Martin.
Eminem's challenge came down from his old friend and mentor Dr. Dre, who completed the task with an elaborate contraption earlier this week before nominating Kendrick Lamar and Snoop Dogg, in addition to Eminem. "I gotta admit it was a little bit shocking," he said afterwards. Lamar accepted the challenge and passed it on to Serena Williams, Ellen Degeneres and Smauel L. Jackson. Watch Dr. Dre and Kendrick Lamar get drenched in the videos below.