The message
from Grimly Curmudgeon contains these words:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Appin saying
something like:

If the engine's allowed to stop, and the whole
vehicle gets cold it's likely to be a case of having to use a blowtorch
on the fuel tank and fuel lines in order to get going again.

And the sump, if it gets cold enough.

In those parts every sump has a sump heater and batteries have either a
heated pad underneath them or a heated blanket around them. Both
normally powered by mains voltage. In cities like Winnipeg in Canada
even the parking meters have power connections so that you can plug in
your car's sump and battery heaters when you park your car. There's
normally a trailing plug coming through the radiator grille. No chance
of a battery working at -30 degrees Celsius.