back in the mid 1950s when the experts were predicting the next ice age was coming, we had an IH SC and a JD 420U. We would leave the JD in our woodlot that was 7 miles from the farm and no electricity for 3 miles. The JD would start good to about -30F but when it got to -35F the only way to start it was to build a fire under the oil pan. Yes we used 10W oil. Dad had an old hub cap off a 49 Chev that he would half fill with chain saw gas, place it in the snow under the oil pan of the JD and toss a match in it. When the gas was all burned then the JD would start but shifting gears was another story. You had to leave it the gear the night before that you were going to use the next day. When we traded the JD in 1969 for an IH 434 the IH Dealer asked what caused the black marks on the oil pan.
Back on the farm with the SC when it was really cold Dad would never try to start it with the starter, he would leave the ignition off, full choke, part throttle, give it a couple rev with the crank, then turn on ignition, and 1 up pull on crank with hand cupped it would start. He taught me how to safely crank a tractor. That same winter a neighbour wasn't so lucky starting his Case as it kicked back and broke his arm.