There are dozens of probable causes for a no start condition.
What was given in the previous tread are all probable causes but dont't forget"
a)The ignition system
b)Fuel system, including the cold start injector
The weather has been brutally cold here over the last 2 weeks with temperature down to minus 36deg. My old faithfull Benz with 246K on the clock never failed to start. I only have to present him my remote starter and it start right up with less than a full turn on the starter.