How to solder a 70 °C (158 °F) thermal / temperature fuse
This was a problem with transistors in the early days and standard advice was to use a pliers as a heat shunt close to the body of the component.



Figure 1. Protecting a capacitor from overheating when using a big ignorant soldering gun. Image source: Mother Earth News.

Oddly enough, the image above was the only one I could find in an image search. The technique may be getting lost. A long nosed pliers with a rubber band on the handles may suffice and the rubber band will hold it in place freeing up one hand.