Back around, oh, the late 1970s or early '80s, I used to notice signs in restaurants with the warning, “Microwave oven in use”. It was explained to me that microwave ovens could interfere with/stop the functioning of pacemakers, so the sign was there to let people with pacemakers of the potential risk.
It occurs to me that I haven’t seen one of those signs in years and years, which would suggest that the risk is no longer there or is greatly reduced. So what changed? Better shielding on microwave ovens? Changes to pacemakers to make them less vulnerable?
Restaurant microwave ovens used to be higher power and not as well shielded as home microwave ovens. Modern ones still can be much more powerful, but the shielding is better (better designs using cheaper materials).
Pacemaker designs have improved rather dramatically in the past couple of decades as well. There may be some folks still out there with older designs and they have to be more careful about any type of radio wave interference (microwave ovens, arc welders, etc) but folks with modern pacemakers don’t need to worry so much.
I’m glad this isn’t a “need answer fast” thread!