Pots and are sensitive for heat while soldering. They can overheat, melt or just break.
To prevent this from happening you can use a copper alligator clip as heatsink. The alligator clip soaks up the heat before it reaches the part.
The copper alligator clips become really hot while soldering. The clips are supplied in sets of 2 so you don't habe to wait for the clips to cool down.