Dressed in a white T-shirt, the actor took part in the ALS Bucket Challenge. The movement raised awareness, and funds, for Amyotrophic lateral sclerosis (aka Lou Gehrig’s Disease).
The rules of the Ice Bucket Challenge state that, once you have been nominated, you have just 24 hours to pour a bucket of ice-cold water over your head. Once you have completed it, you must nominate three other people to do it. Failing to complete the challenge in the time frame calls for a donation of $100 to ALS research.
Firefly actor Nathan Fillion originally nominated Hiddleston, who then went on to nominate Luke Evans, Helena Bonham-Carter and Benedict Cumberbatch.
ALS, or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. A-myo-trophic comes from the Greek language. "A" means no. "Myo" refers to muscle, and "Trophic" means nourishment – "No muscle nourishment." When a muscle has no nourishment, it "atrophies" or wastes away. "Lateral" identifies the areas in a person's spinal cord where portions of the nerve cells that signal and control the muscles are located. As this area degenerates, it leads to scarring or hardening ("sclerosis") in the region.
Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise. When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. With voluntary muscle action progressively affected, people may lose the ability to speak, eat, move and breathe. The motor nerves that are affected when you have ALS are the motor neurons that provide voluntary movements and muscle control. Examples of voluntary movements are making the effort to reach for a smart phone or step off a curb. These actions are controlled by the muscles in the arms and legs. ALSA
The Ice Bucket Challenges that may have changed the medical world
By Michael Baggs, Newsbeat reporter
27 Jul 2016
In 2014, thousands of people, including celebrities, were soaking themselves as part of the ALS Ice Bucket Challenge. Money raised from the online craze has now resulted in a breakthrough in Motor Neurone Disease (MND or ALS) research.
The University of Massachusetts Medical School's Project MinE was donated $1m from funds raised by the challenge. It has since discovered the NEK1 gene, which contributes to the kind of MND which is passed on in families.
"This discovery identifies exactly what one of those contributing factors may be towards developing MND," Belinda Cupid, head of research at the UK Motor Neurone Disease Association, tells Newsbeat. "It's a small thing that won't cause MND on its own but it makes us understand a little bit more so we can develop treatments quicker."
It means getting doused in ice cold water in your garden two years ago could have had a big impact on the medical world.
"Two years might seem like a long time ago to a lot of people who don't have a connection to Motor Neurone Disease," says Belinda Cupid. "But to people living with MND and researchers who are working in this area, the Ice Bucket Challenge feels like it was two minutes ago."
The gene was discovered in the US, but the Ice Bucket Challenge also resulted in a huge financial boost to UK based research.
"In the UK, we put £5m of the Ice Bucket Challenge money into MND research," she adds. "I've never seen so much money raised in such a short amount of time for MND. It was phenomenal."
While the discovery of the gene is a big breakthrough for research, familial MND affects just 10% of sufferers. However it could lead to much greater understanding of the disease.
"We're always hoping for a cure but it's more realistic to say what we want to do is stop the disease in its tracks," says Belinda. "The goal is for someone to go into a doctor's surgery or hospital and say yes, you've got motor neurone disease but take this pill and it won't get any worse."
The Ice Bucket Challenge may be a 2014 phenomenon but fund raising stunts continue to bring in much needed finances to MND research across the world.
"There's currently a Silent Speaks fundraising and awareness campaign," Belinda says. "Over 80% of people with MND lose their voice, so this is a fantastic way young people can get involved, stay quiet for an hour, a day. "Some people have even done it for a week."
For more information visit MNDassociation.org