Apple, the FDA, and a 2022 cardiology study all give the same guidance: keep consumer electronics at least 6 inches from an implanted heart device, because the magnets inside them have grown strong enough to flip a built in safety switch.
Apple's own support page says it plainly: keep AirPods, iPhones, and the Apple Pencil at least 6 inches (15 cm) away from an implanted heart device. The FDA gives the same distance, and a 2022 American Heart Association study showed why. The rule exists because the rare-earth magnets in current-generation gadgets can flip the safety switch, called magnet mode, inside pacemakers, defibrillators, and other cardiovascular implantable devices (CIDs). That switch, designed to pause therapy around strong fields, triggers at about 10 Gauss, roughly the strength of a small fridge magnet.
When a CID enters magnet mode, a defibrillator may stop watching for dangerous rhythms, and a pacemaker can switch to a fixed pacing pattern that ignores the heart's own signals. Therapy returns the moment the field goes away. The 10-Gauss threshold is the line the device uses to decide it is standing next to something too magnetic to ignore, the way an MRI room is too magnetic to enter.
Engadget's explainer by Alec Hively, published 2026-06-13, reports that the 2022 bench study, which tested AirPods, the iPhone 12 Pro Max, the Apple Pencil, and the Microsoft Surface Pen, found each one produced magnetic fields strong enough at close range to push a CID into magnet mode. Comparable interference has been documented for smartphones, smart watches, and e-cigarettes. Older consumer devices sat comfortably below the 10-Gauss line. Today's earbuds, phones, and styluses, packed with rare-earth magnets for cases, speakers, and magnetic charging, cross it. That shift, not any single product, is why the conversation keeps resurfacing.
Apple's support article on potential medical-device interference, article 109025 published 2024-02-02, uses careful language, noting that implanted pacemakers and defibrillators "might contain sensors that respond to magnets and radios when in close contact" and recommending 6 inches (15 cm) of separation, or 12 inches (30 cm) when wirelessly charging. Apple is not telling users to stop wearing AirPods. The FDA echoes the same distance and adds a practical warning: avoid putting phones, watches, or earbuds in a shirt pocket over the implant.
The FDA also writes that a patient whose CID is paused by a magnet "may experience dizziness, loss of consciousness or even death if therapy is not delivered when lifesaving shocks are required." That is the regulator's worst-case framing for a theoretical event, not a count of measured injuries. No major study has tallied how often magnet exposure actually disables a CID in daily life, and the agency has not asked patients to abandon earbuds. The guidance, repeated by Apple, the FDA, and the cardiology literature, is distance, not avoidance.
For the millions of people with pacemakers, defibrillators, or other implanted heart devices, the practical action is small: keep phones, watches, earbuds, and styluses at least 6 inches from the implant, treat a shirt pocket over the device as off-limits, and ask a cardiologist if a specific gadget is a concern. For everyone else, the takeaway is a clearer mental model. The rare-earth magnets that make modern consumer electronics feel magical can also trip a safety switch in someone nearby, and the fix is a pocket, a drawer, or a different ear.