The plastic covered thermal fuses and the metal tubular thermal fuses that have one wire coming out of each end contain a small blob of metal that melts at the temperature stamped on the fuse. These are not resettable no matter what you do, since the actual metal has melted, leaving a gap.
The high limit thermostats contain a bimetal disc. but I've never tried a reset because I'm not sure if it would trip correctly a second time and I don't want to test my liability insurance. 8-) It's not meant to be reset, so I don't.