Former President George W. Bush took the ice bucket challenge then nominated former President Bill Clinton to do it next.

The challenge has caught on with notable figures participating in the campaign to raise money for the fight against ALS, or Lou Gehrig's disease.

In a video posted Wednesday on Bush's Facebook page, he says: "To you all who challenged me, I do not think it's presidential for me to be splashed with ice water, so I'm simply going to write you a cheque."

The video, taken in Kennebunkport, Maine, then shows a smiling Laura Bush dousing him. She says: "That cheque is from me — I didn't want to ruin my hairstyle."

On Mobile? Watch the former president's cold shower here.

Prime Minister Stephen Harper was nominated to experience an icy-cold shower of his own for the cause. On Twitter Monday he thanked "everyone" for the nominations, but said he and his wife Laureen would be making a donation instead.

Liberal Leader Justin Trudeau doused two Liberal MPs, Sean Casey and Rodger Cuzner, during a break in their caucus meeting in Edmonton Tuesday. He also made a donation to ALS in lieu of his own big chill.

With files from CBC News