Carrie Underwood Takes on Super-Sized Ice Bucket Challenge, Taylor Swift and Robert Downey Jr. Also Share Videos—Watch!

They are among scores of people, famous and non-famous, who are dumping ice water on themselves to promote awareness for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.

Carrie Underwood has taken the ALS Ice Bucket Challenge to the extreme!

Instead of a bucket, the singer and husband and NFL player Mike Fisher had a man in a bulldozer use the construction vehicle to dump freezing water on them. Underwood posted the video on her YouTube page on Saturday.

Scores of people, famous and non-famous, have been sharing videos showing themselves being drenched in ice water to promote awareness for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease. The campaign started about a month ago and has in recent weeks become more popular, namely due to posts shared by stars.

Participants are also asked to encourage others to follow suit. Underwood challenged fellow country star Jennifer Nettles.

Also on Saturday, Taylor Swift and Iron Man himself, Robert Downey Jr., shared their own videos. Swift took on the challenge with friend, actress and model Jaime King. She shared on her Facebook page a video of the two surrounded by about two dozen people dressed in black T-shirts at the pop and country singer's rehearsal for the 2014 MTV Video Music Awards. The two held several bills in their hands and Swift said they would donate $100 for every person there to raise awareness for ALS.

Swift challenged friends Selena Gomez, Emma Stone and Ed Sheeran.  

Post by Taylor Swift.

Downey posted on his Twitter page a clip of himself undergoing the task shirtless, courtesy of his pregnant wife, Susan Downey. He challenged Avengers co-star Chris Hemsworth and Vincent D'Onofrio, who appears with Robert in the new movie The Judge, to go next.

Hemsworth! D'Onofrios! U have 24hrs to comply!! #ALSicebucketchallenge https://t.co/mGbcnFGP3O

? Robert Downey Jr (@RobertDowneyJr) August 16, 2014

Kerry Washington of Scandal also took the Ice Bucket Challenge, accepting TWO ice water buckets (and looking stylist as always), as seen in an Instagram video posted on Friday.

Like Downey, Stephen Amell of Arrow also appeared shirtless for his Ice Bucket Challenge, as seen in a YouTube video posted on Friday, and like Underwood, he changed the rules a bit—he opted to have ice cubes, rather than water, dumped on his head.