At least at 105 degrees you can still go out at night or early in the morning to do your chores. At -40 you can't go out anytime. Not even sure how you stay warm in your house. Not sure how cars and other equipment work...
You can go out, you just can't stay outside. I started my car this morning (no issue, but it was in the garage) then went to start my daughter's car, which was outside, and pull it into the garage. Slow to start but it did. Need to brake early and hard because they're slow to react when the brake fluid is that cold. Cars make ungodly sounds at these extreme temps.
Houses are insulated so well you wouldn't even know it's cold outside.
Nobody really works outside jobs when it's this cold. Construction crews are sent home. My former BIL was in that situation a while ago.
The other thing about this cold is that if you breathe in through your nose, your nostrils can literally freeze together for a quick second.
You don't want to run out of gas or break down, and if you do, you stay in the car without opening the door, until someone gets there to help. Crazy weather but it will be 35 degrees Saturday (I know how cold that seems but it will feel really warm in comparison).