Cleveland Cavaliers star LeBron James was called out by a slew of celebrities and athletes to complete the Ice Bucket Challenge, and he did just that Sunday.

James posted the clip to his Instagram account, and had a huge bucket of ice water dumped on his head while he sat on the deck of a boat. The viral fundraising effort started by the Pete Frates Foundation has helped raise millions for ALS, or Lou Gehrig’s disease, research. According to Time, since the challenge started more than 150,000 donations totaling $5.5 million have been made.

A former Boston College baseball player, Frates was diagnosed with the progressive neurodegenerative disease in 2012. Though he can no longer speak due to ALS, Frates started the sensation by posting his own video on Facebook on July 31 with Vanilla Ice’s “Ice Ice Baby” playing in the background.

James accepted the challenge from fellow NBA star Kevin Durant and comedian Kevin Hart, and followed suit by nominating president Barack Obama. Unfortunately, James might not have heard that Obama has already turned down the challenge, but pledged to make a donation. Or maybe he's hoping Obama will reconsider.

The craze for a worthy cause has taken over social media sites Facebook, Twitter and Instagram, with a number of professional athletes and teams joining in. The entire New England Patriots squad, along with owner Bob Kraft, completed the challenge and nominated the rival New York Jets, who then got really creative and doused the players with an elevated fire hose while calling out the Cleveland Browns.