The World Health Organization has plenty of details on how you should properly wash your hands to protect yourself against infection and to prevent the spread of flu and coronavirus. But if we wash our hands and then suddenly switch back to our phone, we're exposing ourselves to germs all over again.

Several studies, including one published by the U.S. National Library of Medicine in 2017, have suggested phones can contain lots of germs. So if you're washing your hands, you should probably also keep your phone clean.

Here's what you should do.

Turn off your phone before you start to clean it.

Apple recommends using a lens cloth, the sort you might use to clean your glasses. If you have an iPhone 7 or higher, which are more water resistant, you can also use a cloth with a small amount of warm soapy water, as long as you avoid getting that water into openings on the phone. Other phone makers don't specifically say that this works, though you should generally be safe with most modern phones released in the past several years that have some sort of water resistance.

Apple and Samsung advise against using cleaning products, since they can damage the fingerprint-resistant coatings on the screens. But desperate times call for desperate measures and I've found I'm more worried about germs than fingerprints on the screen. For years I've gently wiped down the screen with a Clorox wipe, or diluted rubbing alcohol against recommendations without any issues. Just be careful and, again, try to avoid getting them in the ports.

If you are worried about damaging the screen, consider buying a cheap screen protector and just using Clorox or Lysol wipes to clean it. You can always replace the screen protector with a new one. Gently wipe down the back and sides of the phone, too.

On older phones, you should just use a soft, lint-free cloth, since those phones aren't resistant to liquid. One popular microfiber cloth brand that I've used for a long time is called Toddy Gear, but there are lots of cheap microfiber cloths on Amazon, too. I just can't speak to the quality of them.

In general, you should probably just wash your hands before using your phone, and then use a hand sanitizer like Purell after you use it and before you touch your face.

If you're speaking on the phone a lot, consider using headphones to avoid bringing your phone up to your face as frequently. While headphones like AirPods aren't germ-free either, you can clean the outside with isopropyl alcohol, making sure not to get any inside the AirPods. It's important not to use household cleaners, however, since they'll go back inside your ears.

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