Teflon tape,,,Sensor safe ???

Is teflon tape sensor safe in the cooling system ??

I use Teflon take on virtually everything. It ensures that I won't have a leak, and I can remove it later. The only thing is don't let it get into any of the internals of the engine, Teflon doesn't break down and could clog someting, causing a bad result.
Also I hope you don't mean to use it on O2 sensors!