Some people like to sing while scrubbing up in the shower, but physicians say we should also be belting out tunes—specifically, two renditions of "Happy Birthday"—while washing their hands, according to The Guardian.

Cold and flu season is swiftly approaching, and keeping your hands squeaky clean is a key way to avoid getting sick and spreading germs to those around you. That said, some people might not know the optimal time span to suds up at the sink, which is 20 seconds if you’re to fully rid your hands of harmful viruses and bacteria.

Instead of breaking out a stopwatch, the Royal Pharmaceutical Society (RPS)—the professional membership body for pharmacists in Great Britain—has recommended that people sing two rounds of "Happy Birthday" during each hand washing session. Not a fan of bathroom karaoke? Try humming it instead. (Singing it silently in your head works, too.)

This raises the question: How do germs get onto our hands and make us sick in the first place? For one, they can be contracted by touching an object that someone coughed or sneezed on. Germs from fecal matter—which come from using the toilet, changing a diaper, or handling raw meats that have invisible traces of animal poop on them—also play a part, according to the Centers for Disease Control and Prevention (CDC).

When people touch their eyes, nose, and mouth with germy hands, or prepare food with them, they’re inadvertently making themselves sick. And since germs from unwashed hands can be transferred to surfaces like handrails, tabletops, or toys, people who routinely skip hand-washings are also putting others at risk for illness.

CDC officials say that proper hand-washing can ultimately reduces antibiotic use—thus decreasing our chances of developing antibiotic resistance—and also prevent about 30 percent of diarrhea-related sicknesses and 20 percent of respiratory infections, like colds. That said, not everyone does their due diligence at the sink, especially after touching animals, going to the bathroom, or preparing and eating meals.

According to a poll of more than 2000 people conducted by the RPS, 84 percent of people don’t wash their hands for long enough periods of time. Meanwhile, around 65 and 32 percent of people don’t wash their hands before eating or preparing food, respectively, half of them don’t after touching pets and other critters, and 21 percent don’t after a trip to the toilet.

These stats have you concerned? Here’s a primer to perfecting your hand-washing technique.

[h/t The Guardian]