I've always figured the electric heat units were for Californians, who think
that if it gets too cold you just take off your skis and go home.  I know
what a small and localized help a hairdryer is when I'm working in my un-
heated garage in 19oF. weather.  All it does is keep the socket wrench from
sticking to your hand.  And the in-car electric heaters are in that range of
wattage, I think.  So I would go gas or propane, for serious cold, especially
in a van were you have some big rectilinear places to put 'em.

I don't know what a 13-year-old working gas heater is worth.  Maybe someone
else in the group does?  Nor do I know how much gas it uses -- never used it
that consistently.  At -30oC., do you really care?
B.