Usain Bolt takes ALS Ice Bucket Challenge to raise awareness for ALS, also known as Lou Gehrig`s Disease.
Participants dump a bucket of ice water over their head (usually without using a metal girder and not on their own private dock, like Mr Gates), donate $10 to the ALS Association, and nominate three other people to take part.
The disease is a progressive neurogenerative disease that affects nerve cells in the brain and spinal cord eventually leading to paralysis and death.