Celebrities are more used to putting their champagne into an ice bucket than pouring the contents of the container over their heads. Now stars from the world of sport, fashion and the big screen are queuing up to take part in the ALS Ice Bucket Challenge - raising money for Amyotrophic Lateral Sclerosis or Motor Neurone Disease as it is better known in the UK.
Oprah, Justin Bieber, Britney Spears, Bill Gates, Mark Zuckerberg, Lady Gaga, Charlie Sheen and George Bush have all posted videos of them taking part in the icy fundraiser online. Here's a selection of famous Londoners doing the same...
David Beckham nominated Magic Johnson, Michael Jordan and Leonardo di Caprio.
Victoria Beckham nominated Tom Ford, Katie Holmes and son Cruz Beckham.
Actor Ricky Gervais nominated Russell Crowe.
Jose Mourinho nominated his daughter, Bryan Adams, and James McAvoy.
Arsenal players Alex Oxlade-Chamberlain and Kieran Gibbs nominated fellow Londoner and Liverpool player Rahim Sterling, Watford born boxer Anthony Joshua, Manchester City player Bacary Sagna and referee Andre Marriner who wrongly sent off Gibbs last season after Chamberlain handled the ball against Chelsea.
QPR player Rio Ferdinand nominated James Corden, Lionel Messi, Drake, Trey Songz and Zlatan Ibrahimovic.
Arsenal footballer Theo Walcott nominates best friend Jake Thompson, former Arsenal player Thierry Henri and no less than Prince William!