This summer marks the 10th anniversary of the ALS ice bucket challenge.
The campaign saw people worldwide dumping ice water on their heads to raise money for care and research into ALS, also known as Lou Gehrig's disease.
The ALS Association credits the global effort with "forever changing the future and trajectory of ALS."
In 2014, 17 million people helped raise $115-million with the challenge.
The charity shares how the challenge works and invites people to do it again.
Celebs that took part included The Rock, Tom Cruise, Reese Witherspoon, and Tom Hanks.