The last ditch engine start technique for temps here in Canada for days below -25 deg C at the family garage was to take a pint pouring can (with thin spout), put a few ounces of gasoline in it, light it, and pour fire directly into the open intake while cranking the engine.
Extremely dangerous, not the done thing these days I am sure, but it worked, particularly on very large gasoline and diesel engines. Definitely worked better the older the engine was. We worked on cars trucks and tractors from the 1920's to the 1980's in the family shop.
Nowadays you would be challenged on most cars and trucks to find a vertical intake hole of any kind to pour the fire into.
We got many calls for "engine won't start" on such days, on locally used cars, mostly 1960's-1970's US made ones. Dad had rigged an extra long set of heater supply and return hoses into the 327 Chev V-8 in our service truck. He arranged end-of-hose valves and couplers so that on such calls he would disconnect the heater hoses from the car's engine block and connect in the long ones from the service truck's running engine. 5 minutes of hot circulating coolant and 9 out of 10 engines would start just fine. Another 5 minutes to disconnect hoses / fix car's coolant level , return to the garage where the phone was ringing off the wall, and then send a bill for $25 whole dollars. Without the hot coolant many cars just would not start at say -30 deg C regardless of what you tried or for how long.
Edited By Jeff Dayman on 16/02/2021 20:09:29