Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with various causes. It is characterised by muscle spasticity, rapidly progressive weakness due to muscle atrophy, difficulty in speaking, swallowing, and breathing. ALS is the most common of the five motor neuron diseases.
The challenge went viral on social media earlier this month. A contestant fills a bucket full of ice and water. They then state who summoned them to do the challenge and will summon three other individuals of their choice to take part in it. The contestant then dumps the bucket of ice water over themselves.
Many celebrities have taken part in the challenge so far, including, Cristiano Ronaldo, David Beckham, Cheryl Cole, Vince McMahon and George Bush.