See R-Pattz, Zac Efron And Gwynnie Take The Ice Bucket Challenge

Robert Pattinson's a pretty cool customer at the best of times, but the Twilight star got even more chilly this week when he took the ALS Ice Bucket Challenge.

R-Pattz was nominated for the charity fundraising stunt by his actor pal Zac Efron - and has posted his effort on YouTube.

Wearing a white T-shirt and backwards baseball cap, the 28-year-old heart throb explained that "it was short notice and I had to improvise".

He is then seen having a (quite small) saucepan of ice poured over his head before being doused with a garden hose by a friend.

And he then struggles to think of who he'll nominate in return - before deciding on Guy Pearce, Mia Wasikowska and Marilyn Manson.

All that money and he can't even afford a decent-size bucket!

Mr Efron had previously taken his challenge along with former High School Musical co-star Ashley Tisdale.

But to the disappointment of many of his fans, he kept his shirt on for once as he took his dousing like a man.  

Gwyneth Paltrow has also taken up the challenge - having been nominated by US TV legend Martha Stewart and others.

She posted a video on her Instagram page showing herself standing on the lawn in a bikini and pledging to donate money, before an friend enters stage left and pours a large container full of water over her - causing them both to squeal with alarm and delight respectively.

Gwynnie laid the gauntlet down to Cameron Diaz, Stella McCartney and estranged husband Chris Martin - leading wags to suggest that she thinks he needs a cold shower (after being linked to Jennifer Lawrence).