All you do to take part is wear a Christmas jumper that day, wherever you go, and make a donation of £1 to Save the Children.
No need to shave your head or balance something on your nose - just put on your favourite (ie Woolly Babs) Christmas jumper and off you go.
There's a large celebrity element to the day with all sorts of people wearing their Christmas jumpers with pride.
Keep an eye out for the Woolly Babs jumpers as there's a few in circulation... especially our dog jumpers!
Save the Children were delighted to use those for their photo shoots and to pass on to celebrity dogs to raise even more awareness around the day.
So when you're keeping your eye out, look down towards the pavement too.
You can go beyond just wearing a jumper and donating £1. Save the Children have loads of resources for how you can get people active whether it's a school, office, building site, farm....
Just start searching their website for resources.