Ivan Vegvary wrote:
Replacing thermal fuse in wall oven power supply.
Does fuse measure temperature of ambient, or, temperature based on current through fuse?

It just measures heat, doesn't matter where it comes from. But-

Keep in mind heating the fuse with current will heat the inside to a
higher temp that just warming the outside as there is thermal resistance
of the device package to overcome.

Just be careful soldering the leads and you should be ok.