Originally Posted by Tom S.

The idea of putting heat to the screw isn't the same as taking off a rusty manifold. The reason for the heat is to break the bond of factory applied thread sealer, and is common practice for removing screws held in place with Lok-tite type products. In many cases, a soldering iron works great for this process. You aren't trying to get the screw red hot, just warm enough to break the sealant's bond.