Short pieces of 2 or 3 inch steel strapping can be obtained free at any steel fabricator that uses steel strapping. Placing the steel immediately around the tile to be removed protects the adjacent tiles from heat so that the adhesive holding them down doesn't even soften.
I find that when I remove a vinyl composition tile, the steel strapping around the tile I'm removing will barely even be warm despite the hot air blown on the steel in removing the tile. I expect that's because steel is dense, and it takes a lot of heat to warm it up.
Also, if you use a pry bar like this one:
It's sharp and flat enough that you can simply heat the tile from above and slide the sharp end through the glue layer to lift the tile off the floor without pulling up any floor leveler (or in the case of P&S tiles, primer adhesive).
And, the tool above is actually used by bee keeper's for scraping the honey off hives. If you go to any apiary supply store (beekeeper's supply), you can find these tools in different sizes and shapes:
The larger 10 inch tools are commonly available in hardware stores, but the other sizes and styles seem to only be available in bee keeper's supply stores. Beekeeper's supply stores will often stock these same tools in stainless steel as well as spring steel.