It's come up a few times in the last fer months.
The 30 year old space heater that my wife uses finally died.
Decided to perform an autopsy:
Right above the motor is a small thermal breaker in series with a
thermal fuse. The breaker , with age became over-sensitive and would
rapidly cycle off after running just a few minutes.
Got a replacement heater from the hardware store for $20
Decided not to foolishly bypass the safety device.