Apple is warning owners of new iPhone 12 models to be sure to keep what it calls a “safe distance” away from medical devices such as implanted pacemakers and defibrillators.

The warning also applies to MagSafe brand accessories.

“iPhone contains magnets as well as components and radios that emit electromagnetic fields. All MagSafe accessories (each sold separately) also contain magnets—and MagSafe Charger and MagSafe Duo Charger contain radios. These magnets and electromagnetic fields might interfere with medical devices,” Apple says in the warning.

“Though all iPhone 12 models contain more magnets than prior iPhone models, they’re not expected to pose a greater risk of magnetic interference to medical devices than prior iPhone models.

“Medical devices such as implanted pacemakers and defibrillators might contain sensors that respond to magnets and radios when in close contact. To avoid any potential interactions with these devices, keep your iPhone and MagSafe accessories a safe distance away from your device (more than 6 inches / 15 cm apart or more than 12 inches / 30 cm apart if wirelessly charging). But consult with your physician and your device manufacturer for specific guidelines.”

Read the full warning online.

The warning was published Saturday and first reported by Apple news site MacRumors.