Why not to use portable heater while driving

SuzzeeeQ2012 wrote:
it gets cold in the cab. We have a Class A and we're trying to heat 37 feet of motorhome while driving. The heater in the dash just can't keep up. Won't be driving with the Blue Flame on after seeing this though

While going down the road, why can't you run the built-in generator to power two or three safely secured electric heaters in the coach area to keep it fairly warm back there? Seems simple enough to me, if you are willing to sacrifice some gas mileage.