Here is an interesting idea that makes very cold diesel starts possible.   

    As the temperature drops, diesel owners begin to worry because the paraffins found in diesel fuel easily solidify. Obviously if your fuel freezes it will not be able to flow into the engine. Jorge Vazquez of the Universidad Pontificia Comillas has come up with a solution.

First of all lets try to find exactly where the problem exists. Let's say it is -40 degrees F and there is a stiff 30 mph wind and your truck has been exposed to these conditions  uncovered overnight. You put the key in and try to start the engine. Amazingly the batteries still have juice and the engine cranks and cranks but no fire, what happened?

In this situation the entire fuel system has froze, but when you cranked the engine the fuel pump created enough heat to push slushy fuel it had in it into the engine. The problem is the fuel behind it is frozen-especially in the filter. Traditional solutions include an electrical resistor heater that keeps the fuel in the tank and filter liquid. The problem is what happens when you don't have a plug in? Another problem is the electricity is a constant drain.

Vazquez's solution  is to let the fuel freeze and then warm it back up only where it needs it- inside the fuel filter. The tank and fuel lines will warm up once the engine is started.

Instead of using a constant draw of electricity to keep the fuel filter's fuel liquid. This new concept stores heat in a eutectic compound while the engine is running. This compound retains heat for a long time. Seconds before start up the heat is then transferred into electricity by using a thermoelectric device The electricity heats a small wire that is run down the center of the filter. Thermoelectrics take temperature differences and produce electricity or vise versa.

Benefits of this system include:
1. The entire fuel heating system is packaged in the fuel filter.
2. It is self sufficient energy wise.