Building a heater into rear defroster blower hose

Yes I would assume a production piece has thermal protection. I agree that cheap china man product may suck.
The inference is: get something with thermal protection.
Wiring with 12 gauge, fuse and relay off battery or terminal post was entailed.
:)
I mean we are not engineering systems with all certifications here, we are suggesting processes which the integrator has to use his own diligence as a final determination of viability.