If your patients fall asleep with their phones in their beds, consider talking to them about reasons not to, as ABC News reports.

There’s been no research that proves cell phone use causes cancer; in fact, the links to any kind of health risk aren’t yet clear. In general, cell phones are said to give off such small doses of electromagnetic radiation—which is also emitted from X-rays and microwaves and can lead to tumor growth in high amounts—that they’re perfectly safe to handle.

Still, the World Health Organization warned in 2011 that usage may be possibly carcinogenic to humans, especially in children, whose scalps and skulls are thinner than adults’, and more vulnerable to radiation. So if you’re at all worried about the possible cancer risk, try to text instead of call, hold the phone away from your ear, or use an earpiece or the speakerphone setting as much as possible—and definitely don’t sleep with the phone next to your head.