What happens to an engine during a cold start in sub-zero temperatures?

pishta said
Think back how many old cars in Canada would start right up in -20 with just a choke. Start it up and run back in the igloo for 15 minutes.

Choke? We don't need no steenken choke, jus' pump da pedal a couple dozens times while you smoke a cigarette, thas all you need ta do eh?