Ignition key is hot - temp wise

I've once had a field wire to the alternator short out and melt everything together upstream while I was driving.

This was in a '64 Chrysler with a dash mounted ign. switch.
When I started seeing smoke coming from under the dash I quickly reached over turned off the ignition and coasted the car to the side of the road.
While turning the ignition key I already noticed the key was warm and the switch internals had almost melted because it took more force then usual to turn the key off.