It would need to be a fuse on each branch of the heating element. And even so, sometimes a defect in one line of the heating element causes it to catch on fire anyway due to the concentration of current.
I mean, this depends on the layout of the heating device. It could also just be a metal plate with a single heating element underneath, using metal to distribute the heat.
Wouldn’t a fuse be enough to prevent that?
Yes, which is why all of them have a fuse on the cord. It’s the same as modern heated blankets.
Is a fuse sufficient, or would one need a GFCI as well?
It would need to be a fuse on each branch of the heating element. And even so, sometimes a defect in one line of the heating element causes it to catch on fire anyway due to the concentration of current.
I mean, this depends on the layout of the heating device. It could also just be a metal plate with a single heating element underneath, using metal to distribute the heat.
Oh that’s a good idea: cut a thin metal sheet and sandwich it between the heater and the bedding.