Former president George W. Bush has taken the so-called Ice Bucket Challenge in support of Lou Gehrig’s disease research, and challenged his Democratic predecessor Bill Clinton to do the same.

“To you all that challenged me, I do not think it’s presidential for me to be splashed with ice water,” Bush says while sitting on a sunny porch dressed in a T-shirt.

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“So I’m simply gonna write you a cheque,” he adds in a video posted on YouTube on Wednesday.

His wife Laura then appears and douses Bush in icy cold water. The former president, who served from 2001 to 2009, lets out a loud “oww” in shock and pain.

“That cheque is from me, I don’t wanna ruin my hairstyle,” Laura Bush says, bucket in hand.

Bush then nominates Clinton to be next. “Yesterday was Bill’s birthday and my gift to Bill is a bucket of cold water,” the former Republican president says.

Bush’s successor, President Barack Obama, has declined a dare from Ethel Kennedy, the 86-year-old widow of late senator Robert F. Kennedy. Obama promised to make a gift instead.

Steven Spielberg, Justin Bieber, Bill Gates, Mark Zuckerberg, Oprah Winfrey and David Beckham are among the hundreds of celebrities to have recently taken the ALS Ice Bucket Challenge, which has expanded beyond the US across the world.

Since June, several thousand people worldwide have recorded themselves getting drenched, then posted the stunt online and challenged others to do the same, or pledge $US100 to ALS research.

Many have done both, in an effort has raise millions of dollars for the ALS Association, which combats amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease.

About 30,000 Americans have ALS, which attacks the nervous system and eventually leaves victims paralysed.

On Wednesday, the ALS Association said it had already collected $US31.5 million ($A34.08 million) from July 29 to August 20, a huge jump from just $US1.9 million last year.