Washing hands – a brand new trend this year – is taking the nation by storm. But what is it? How do you do it? Why bother?

Here’s a full explainer on the wild and wacky new crazy.

Step 1: You’re going to want to lather your hands with soap (a compound of natural oils or fats with sodium hydroxide or another strong alkali, typically with a perfume and coloring added). This is an important step.

Step 2: Run said hands – with the aforesaid soap – under warm water for at least 20 seconds. To pass the time, sing ‘Happy Birthday’ in your head twice, or think about all your regrets so far in that day. There should certainly be enough to suffice the needed time.

Step 3: Dry your hands. Hopefully there is paper towel present. If not, you may need to use an air dryer or wipe your hands on your pants or the pants of an unsuspecting nearby person.

Why do it? Scientists have yet to find a reason.