Welding with a pacemaker

There are at least three ideas being mixed together here.
Magnetic fields
Electric fields
Electric shock

Magnetic fields from welding come primarily from the welder transformer. It is very difficult to shield from magnetic fields. The metal case of a welder does nothing for a magnetic field. The good news is that the magnetic drops off with the square of the distance. That means that means that if you move from 1 foot to 10 feet away, the magnetic field drops by a factor of 100. So keeping as far away from the welder as possible is a good idea.

Electric fields are caused by the current flowing in the welding cables (magnetic fields are generated too, but are small). A lot of electric field is caused by the arc of the welder. Electric fields can be easily shielded by metal, however the container would need to be well sealed for maximum shielding. Electric fields are also generated by ignition systems. Electric fields also fall off with the square of the distance. Bad news is you can’t stay away from the arc very well when you are welding.

Electric shock has to have a physical conductive path. You have to get your hand on the plug wire, or get close enough for it to arc to you. You don’t have to be very far away to keep from getting shocked. High voltage stand off in air is about 10,000 volts per inch. For a 40,000 volt ignition system, that means you only need to be about 4 inches away. *****edit, did my math backwards*****

Modern electronic devices like pacemakers are hardened to all of the above threats. How much? It is hard to say if you are safe without knowing a lot of detail about the threat.

I don’t really have an answer after this long winded explanation. I just am trying to identify the threats. If you understand the threats you can be better prepared.

If you are worried about magnetic or electric fields, then a drill held too close to your chest could be a big threat.