
I have an AICD or in layman's terms an internal defibrillator. As I'm only in my 40s, my cardiologist chose a device that's MRI resistant. The warning on the iPhone 12 would be a legal disclaimer but the magnetic field that it generates would be way less than that output by an MRI or even a welding machine. It might be prudent not to place the phone in a breast pocket but the manufacturers would have considered the strength of the magnetic field against the potential hazards to that particular demographic.