Entering a public bathroom sometimes feels like playing Russian Roulette with bacteria. Humans have come up with numerous life hacks over the years to minimize the germs we come into contact with, from using toilet seat liners (even though we don’t really need to) to opening the door with a paper towel on the way out (despite the fact that the door knob is one of the cleanest parts of a public bathroom). Being overly cautious isn’t necessarily a problem—except when we ignore one of the best (actual) ways to combat bathroom bacteria: washing our hands.

While it may seem like a minor issue, improper hand washing accounts for nearly half of all food-borne illness in the U.S. And while two-thirds of adults typically wash their hands in a public restroom with soap and water, few people suds and scrub for the recommended 20 secondsFood-related illness and death in the United States. Mead PS, Slutsker L, Dietz V, McCaig LF, et al. Emerging Infectious Diseases. 1999 Sep-Oct;5(5):607-25.Hand washing practices in a college town environment. Borchgrevink CP, Cha J, Kim S. Journal of Environmental Health. 2013 Apr;75(8):18-24.. In the words of Carl Borchgrevink, a professor at Michigan State University who has researched hand washing practices, “There are a lot of dirty hands out there.”

To avoid being another dirty statistic, follow this step-by-step guide for proper technique at the bathroom sink. Plus, learn the truth about common hand-washing myths (Do I need to use hot water? Antibacterial or regular soap? Do hand dryers just spread germs around?). Here’s the low-down on getting those hands clean.

Note: This advice pertains to public restrooms. Private bathrooms tend to be cleaner; according to Dr. Chuck Gerba, a professor at the University of Arizona, the most important bacteria to watch out for at home are those you come in contact with during food preparation.

Yes, you read that right: Scrubbing should last for at least 20 seconds. Twenty seconds might seem like an eternity, especially when you can sprint 40 meters in just over a quarter of that time. But your body—and immune system—will thank you for all of the extra seconds you spend scrubbing microbes off you skin and into the sink. Those bacteria can cause eye infections, skin irritation, digestive problems, and urinary tract infectionsOccurrence of heterotrophic and coliform bacteria in liquid hand soaps from bulk refillable dispensers in public facilities. Chattman M, Gerba SL, Maxwell CP. Journal of Environmental Health. 2011 Mar;73(7):26-9.. To help distract yourself while you scrub, hum along to the “Happy Birthday” song twice (or, if you want to stay hip, once through the chorus of Pharrell’s “Happy” works too).

Now that we’ve covered the basics of hand washing, take hygiene to the next level by keeping the following factors in mind.

1. Water Temperature

Warm water kills germs, right? Well, yes—or at least, scalding water does. Water needs to surpass 130°F to start killing off bacteria on the surfaces of your hands, but most skin can’t sustain prolonged exposure to water at such high temperatures without getting irritatedThe Environmental Cost of Misinformation: Why the Recommendation to Use Elevated Temperatures for Handwashing is Problematic. Amanda R. Carrico, Micajah Spoden, Kenneth A. Wallston, et al. International Journal of Consumer Studies. Jul 1, 2013; 37(4): 433-441.. Hot water used during hand washing has been measured at around 100°F, which is unfortunately irrelevant to the germ-killing process.

Your action plan: Rather than worrying about the heat, select a comfortable water temperature and focus on hand-washing technique. The friction caused from intense scrubbing will get those pesky germs off your hands and down the drain. Best of all, you’ll be helping the environment. Colder water doesn’t require as much (or any) electricity. Given that our hot hand-washing habit in the U.S. consumes about the same amount of carbon as the country of Barbados, now is a good time to switch to cold-water washing for good.

2. Soap

Hand washing with soap seems like a no-brainer. In fact, using soap has been found to reduce the risk of digestive problems like diarrhea by 40 percent, compared to those who only wash with waterEffect of washing hands with soap on diarrhoea risk in the community: a systematic review. Curtis V, Cairncross S. The Lancet Infectious Diseases. 2003 May; 3(5):275-81.. That being said, the type of soap used definitely matters. Despite the marketing claims by antibacterial soap manufacturers, the CDC has found they aren’t “any more effective at preventing illness than washing with plain soap and water.” There’s even studies that have concluded long-term exposure to triclosan—one of the ingredients in antibacterial soap—can create antibiotic-resistant bacteriaOccurrence and toxicity of antimicrobial triclosan and by-products in the environment. Bedoux G, Roig B, Thomas O, et al. Environmental Science and Pollution Research International. 2012 May;19(4):1044-65.. Do yourself a solid and opt for regular soap over antibacterial varieties.

Another important point about soap: The stuff that’s supposed to keep you clean can actually be one of the worst culprits when it comes to spreading bacteria. Dr. Gerba (aka “Dr. Germ”) tested bacteria levels in bulk refillable soap containers in public restrooms in five cities and found higher levels than the CDCrecommends in all of them. That means your hands can have more bacteria on them after you finish hand washing than they did before you started—talk about counterproductiveOccurrence of heterotrophic and coliform bacteria in liquid hand soaps from bulk refillable dispensers in public facilities. Chattman M, Gerba SL, Maxwell CP. Journal of Environmental Health. 2011 Mar;73(7):26-9.!

Refillable soap dispensers can get contaminated in a number of ways: The person who refills them hasn’t washed his or her hands, airborne bacteria enter the dispenser when the lid is open, or the process of diluting the soap from its original powdered form exposes the soap to bacteria. The good news? Sealed-cartridge soap dispensers are becoming more common in public restrooms and appear to fend off bacteria better than refillable dispensers.

Your action plan: Check the soap dispenser to see if it’s refillable or a sealed cartridge. A sealed cartridge is preferable. Sealed cartridge soap dispensers don’t have a space to be refilled at the top and have a built-in nozzle to dispense soap. If it’s hard to tell if the dispenser you’re looking at is sealed or refillable (which is usually is), consider following up hand washing with a pump of hand sanitizer.

3. Faucet

The germiest place in a public restroom isn’t the toilet seat or the doorknob; It’s often the handles of the faucet, Gerba says. One of the firstthings you do after flushing a toilet, which causes bacteria to go airborne and potentially latch onto skin, is turn on the tap. So it seems only logical that bacteria would find a comfy home on the handle. It also means that it’s easy to re-contaminate hands when turning off the water after rinsing.

Your action plan: Automatic faucets solve this problem entirely. If an automatic faucet isn’t available, use a barrier, such as a paper towel, between your hand and the handle. Or opt to use your elbow to turn off the water. If you use your elbow, the bacteria will still transfer from the handle to your body, but it’s better on your elbow than your hand. Adults touch their faces an average of 16 times per hour, which give bacteria plenty of opportunities to enter one of the orifices on the face. Unless you’re extremely flexible, we doubt your elbow will have that much contact with your head!

4. Hand Drying

Like a five-year-old about to hop on a Slip-N-Slide, bacteria believe “the wetter the better.” It’s easier for bacteria to hop from surface to surface with a little liquid mobility, so properly drying hands is an essential part of remaining as germ-free as possible. Paper towels and jet air dryers—those super-powered hand dryers—have been found to be equally effective at drying hands quickly (usually in less than 10 seconds). The older models of warm air dryers take about 45 seconds to adequately dry handsThe hygienic efficacy of different hand-drying methods: a review of the evidence. Huang C, Ma W, Stack S. Mayo Clinic Proceedings. 2012 Aug;87(8):791-8..

These days, public restrooms have newfangled contraptions to dry your hands with names like the Xlerator and Airblade. But despite their fancy names, hand dryers (both jet and warm air dryers) are less effective at lowering the number of bacteria remaining on your hands after washing than good, old-fashioned paper towels.

Your action plan: If you have the option, select paper towels over a jet air dryer or warm air dryer to reduce the number of bacteria that remain on your hands. Just remember to use them sparingly—they come from trees!

5. Hand Sanitizers

Given how many ways hand washing in a public restroom can put your paws in contact with even more bacteria, it might seem safest to skip the sink all together and opt for a few pumps of hand sanitizer. But if your hands are really dirty, resist the urge: The CDC continues to promote hand washing over the use of hand sanitizers, noting that alcohol-based sanitizers have been shown to work well on lightly soiled hands but fall short on hands covered with lots of dirt and grimeA method of assessing the efficacy of hand sanitizers: use of real soil encountered in the food service industry. Charbonneau DL, Ponte JM, Kochanowski BA. Journal of Food Protection. 2000 Apr; 63(4):495-501..

Your action plan: Alcohol-based hand sanitizers are a great option, so long as your hands aren’t too dirty. If the dirt on your hands is visible, opt for hand washing with soap and water.