No amount of sanding/sawing, etc in a home shop can generate enough fine dust in to be a fire/explosion hazard. The dust density needed for this to happen is just not there. The DC sales folks are just out to make money from this baseless fear mongering that they perpetuate. If this danger truly exists then all electric motors used on woodworking equipment would need to be sealed or brushless by regulation and UL approved for use in explosive atmospheres.
So, go ahead and keep warm with your gas heater.
Just some good common sense from an old Fart.