Fuel waxing in cold temperatures
This may have no relevance to aviation fuel, however:
I lived in Germany for 25 years and during that time we had some extremely cold surface temperatures - I remember -27ºc on several occasions.
Having always driven diesel cars - from before the time when "winter grade diesel" was commonly available, I occasionally experienced waxing of fuel with consequent inability to start the car. The waxing either builds up in or causes blockage of the extremely small passages in the injector pump, at a time when fuel in the supply pipeline is still flowing easily.
The wax persists for long after the vehicle has been towed into a heated garage: the rule-of-thumb used to be 24hrs of heat-soak before trying to restart the car.