As the wildly successful ALS Ice Bucket Challenge continues to steamroll its way through social media, raising millions of dollars in the process, producer Rick Rubin -- who's worked with everyone from ZZ Top and Tom Petty to Johnny Cash and the Red Hot Chili Peppers -- has taken the challenge a step further.

Instead of simply dumping one bucket of ice over his head, Rubin immerses himself in a bathtub filled with multiple buckets of ice. You can watch the bone-chilling video above.

Rubin in turn challenged R&B superstar Frank Ocean and actors Owen Wilson and Vincent Gallo to complete their own ice bucket challenge and do their part for ALS research.

A plethora of classic rockers have already taken part in the ALS Bucket Challenge, including Joe Satriani, Aerosmith, Rolling Stones' Ron Wood and Sammy Hagar -- all helping to shine a spotlight on the debilitating disease.

And even though we have to admit it's been quite amusing to watch some of our favorite musicians douse themselves in a buckets of ice-cold water, there are some very real faces behind ALS. A benefit concert for former David Lee Roth guitarist Jason Becker, who has been living with ALS for the past two decades, is scheduled to take place in San Francisco on Aug. 30.

The ALS Association says that roughly 5,600 Americans are diagnosed with the disease each year, but that “as many as 30,000 Americans may have the disease at any given time.” To date, the ice bucket challenge has raised a whopping $40 million for ALS research. As more and more people take part in the challenge, that tally stands to grow even more significantly.