If, like us, your Facebook newsfeed has been filled with everyone from your ex-BF to your friend's mom participating, and you woke up this morning to a news feed full of celebs getting in on the latest charity craze, then you’ll know what the ice bucket challenge involves: A-listers (including cool fashion girls Iggy, CaraSelena and Lena) stripping down and pouring a bucket of ice over themselves in order to raise money for charity. We’re lovin’ the nominations too: Justin Bieber chose to nominate Obama (do it!) before icing himself. 

So what’s the story behind the ice? Well, the money raised from the challenges is going straight to the ALS Association to raise funds for sufferers of neurodegenerative disease, amyotrophic lateral sclerosis. If you’re nominated, you have 24 hours to complete the challenge or you must donate $100 to charity. Amazingly, it’s been reported that an estimated sweet $3 million has been raised already. Ice, ice, baby!