Bill Gates has given himself a drenching after being nominated by Facebook's Mark Zuckerberg to take part in the charity ice bucket challenge.
The video shows the Microsoft boss rigging up an elaborate tipping mechanism to douse himself for the challenge, which raises awareness for ALS, also known as Lou Gehrgi's Disease.
Ahead of his slow-motion soaking, multi-billionare Gates calls on others to take part.
"I'm going to challenge three more people - Elon Musk (of SpaceX and Tesla electric cars); Ryan Seacrest (American TV presenter); and Chris Sanderson (curator of TED).
"You have 24 hours - good luck!"
The challenge has now gone viral and is also being used in the UK by Macmillan Cancer Support to raise backing.