The MagSafe technology found within the latest iPhone models enables wireless charging and allows various accessories to be clipped onto the back of the phone.
This new functionality, however, means the smartphones contain more magnets than prior iPhone models.
Apple warned that the electromagnetic fields emitted by the MagSafe technology could potentially pose a risk to nearby medical equipment.
The issue concerns all iterations of the iPhone 12, including the iPhone 12 mini, iPhone 12 Pro, and iPhone 12 Pro Max, as well as all MagSafe accessories.
“Medical devices such as implanted pacemakers and defibrillators might contain sensors that respond to magnets and radios when in close contact,” Apple explained in a product safety notice published to its support page.
“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/ 15cm apart or more than 12 inches/ 30cm apart if wirelessly charging)."
Apple also advised any iPhone owners that use medical devices to consult their physician and medical device manufacturer for more detailed guidelines.
“If you suspect your iPhone or any MagSafe accessories are interfering with your medical device, stop using your iPhone or MagSafe accessories,” the warning concluded.
The guidelines follow a study published in the journal Heart Rhythm earlier this month, which found that an iPhone 12 could interfere with implantable cardioverter defibrillators (ICD).
An accompanying report stated that iPhone 12 models can 'potentially inhibit lifesaving therapy in a patient particularly while carrying the phone in upper pockets."
The report also referenced other instances where the magnets within fitness tracker wristbands were also able to deactivate an ICD up to distances of 2.4cm.