Can someone explain what this gizmo is?

[EasyGoing1]

Can someone tell me what this gizmo is on this ceramic heating element, and what it does?

(see attached image)

[PA0PBZ]

Temperature switch, opens when a certain temperature is reached, it should be written on it.

[themadhippy]

looks like thermal switch,things get a bit warm it opens,when they cool down it closes

[EasyGoing1]

looks like thermal switch,things get a bit warm it opens,when they cool down it closes

And is that temperature selected because if the heating element got hotter than that, it could be damaged?

[Zero999]

looks like thermal switch,things get a bit warm it opens,when they cool down it closes

And is that temperature selected because if the heating element got hotter than that, it could be damaged?

It depends. There are three different types: auto-reset, manual-reset and non-resettable.

If it's auto-reset, then it might be used as a thermostat, in which case, if there's a risk of fire due to it overheating, there should also be a manual or non-resettable thermal fuse, which might be a different type.

It might be there in addition to a thermostat, in which case, it could any of the three types.

[Siwastaja]

looks like thermal switch,things get a bit warm it opens,when they cool down it closes

And is that temperature selected because if the heating element got hotter than that, it could be damaged?

Or start a fire... Think about someone covering the heater with a cloth, or fan stopping due to failure (e.g. seized bearing).

This being said, it's a PTC heating element which already self-regulates to produce less heat when overheated, but this is an extra layer of safety (and possibly still pretty important, maybe the PTC still runs too hot when covered).

This is very likely a self-resetting one. But those have sometimes very large hysteresis so it might need to cool down a lot before it allows current to flow again.

[valcher]

This is a thermostat, one of many - https://honeyvell.energy/wa-data/public/site/electronics/Honeywell%202455R--00980748.pdf

[BeBuLamar]

Actually the heating element generally won't get damage but what houses the heating element may get damaged and causes fire.