There has never been a more fashionable time to record a video of yourself dumping a bucket of freezing cold water on your head, and for that, we have former baseball player Pete Frates to thank for popularising the social media craze.

Frates, 29, who was diagnosed with a neurodegenerative disease called amyotrophic lateral sclerosis (ALS) - more commonly known as Lou Gehrig's - in 2012, hit upon the idea of challenging friends to perform the act in a bid to raise awareness of his condition on July 29.

The ripple effect after a mere three weeks has been tremendous - with the help of his friend Corey Griffin, Frates' ALS Ice Bucket Challenge inspired a fund-raising viral phenomenon that has inspired some of the most famous faces in the world to take part.

Tragically, Griffin died in a diving accident on Aug 16. The 27-year-old philanthropist reportedly played an instrumental part in the campaign, and had just raised US$100,000 (S$125,000) at a charity event before his death.

Here are some things you might not know about the Ice Bucket Challenge.

1. The challenge has been around for some time

Its origins apparently stem from a challenge posed by athletes. Players would challenge each other to either dump a bucket of ice water over themselves or donate to their charity of choice.

How it works now: people record a video of themselves doing the deed before posting it on a social media platform. They then challenge up to three other friends, who have 24 hours (or 48, depending on who you ask) to take up the dare or donate US$100 to the ALS Association.

2. There is no known cure for ALS

ALS, or Lou Gehrig's disease (named after the renowned baseball player of the same name who was stricken with it in 1939), attacks a person's nerve cells and rapidly leads to total paralysis. The mind of someone diagnosed with it, however, remains sharp.

The average lifespan is between two and five years from the time of diagnosis, although there is an approved drug that can prolong survival by a few months. It is quite rare, affecting approximately 30,000 people in the US.

In Frates' case, his body has atrophied to the point that he can now no longer talk, walk or move his limbs. He communicates through eye gaze technology.

3. Corey Griffin's story

Griffin's father Robert was a well-known philanthropist who founded the Boston Children's Hospital's biggest annual fund raising event.

Following in his father's footsteps, the younger Griffin was a well-loved community figure and corporate high-flyer.

4. How popular the phenomenon has become

As of Aug 20, the ALS Association based in the US had received US$31.5 million in donations compared to just US$1.9 million in 2013 over the same three-week period. It also reported more than 600,000 new donors.

According to Facebook, more than 2.4 million videos had been posted on the social media platform.

5. Celebrities get in on the act - in a big way

The world's richest person Bill Gates, Facebook's founder Mark Zuckerberg and former US president George Bush are just some of the more famous names who have done the challenge, in addition to a host of celebrities and actors such as Justin Bieber, Lady Gaga, Oprah Winfrey and Robert Downey Jr. The craze has also caught on with sports icons such as American basketball star LeBron James and Argentine footballer Lionel Messi.

American and Russian presidents Barack Obama and Vladimir Putin were also challenged.

Here are some examples:

Because he's Bill Gates, he just had to design a contraption to do the task for him.

Former US president Geroge Bush tried to squirm his way out of his nomination by saying he would donate instead, but his wife Laura made sure he'd do both.

Lady Gaga, in a goth get-up and black lipstick, shows the wimps how to do it as she pours the silver tureen over head. She doesn't even flinch.

6. Local stars follow suit

Celebrities in their respective countries have pledged to donate to their favourite charities, and it's no surprise to see our local stars getting swept up in the fad. But given our island's sunny weather, is it more of a reprieve rather than a challenge?

TV host Jade Seah enlists the help of students from her alma mater, Tanjong Katong Girls' School, to give her a good soak.

Actress Rebecca Lim will donate S$1,310 to the Singapore Cancer Society, based on the number of likes she got on her Facebook post accepting the challenge.

And after completing his own challenge, tech start-up entrepreneur Keith Ng nominated Minister of State for Trade and Industry Teo Ser Luck, who appeared to accept it on Twitter.

7. Doing it with a twist

US actor Charlie Sheen eschews the water for a bucket full of money - a cool US$10,000, in fact - which he poured over his head before announcing he would donate all of it to ALS research.

And how about this for a plea to save water - Indian superstar Sonakshi Sinha's bucket contained just a single ice cube. Was she trying to be clever or just chickening out?

If there is one person who could make an ice bucket challenge classy, it would be Sir Patrick Stewart. In his refined take on the challenge, the veteran actor starts by writing a cheque - assumed to be his donation to the ALS cause - and then gingerly pouring himself a classic whiskey on the rocks. No getting wet, no large amounts of ice, and not a word spoken at all.

8. It has its critics

Besides some lambasting the act as a waste of water, others have questioned the narcissism of it. Does it do enough to raise awareness when people merely post videos of themselves but don't donate?

9. Not every challenge ends in success

In these unfortunate cases, the challenge proved more of a hazard than they could have imagined.