Ya or when your body just starts vibrating after 5 mins and your eyelashes freeze when you blink and your lips stick when you close your mouth. -40C is very different on the body then 0C
Honestly, If it's -40C with no humidity and no wind it's really not that bad. You learn to breath differently, slower, through your mouth in an elongated shape so that the air can preheat before it hits your lungs.
That was my experience. When you had severe cold snaps and it was below -35C, usually it was dead calm and no wind.
Felt warmer than -20C with a wind.
Also there can’t really be any humidity at those temps.