-45F is pretty cold. Last weekend in southwestern North Dakota windchill temps were down in the -70F range. It's -51F in my hometown in northern ND right now.
An interesting tidbit was that with the -70F in ND and it being 92F in Miami at the same time there was a 162 degree temp difference in lower 48 states.
I see that the title from that U.S. site does not specify the wind chill in fahrenheit, but that's okay because at -45 it is about -42C, so almost equally brutal and not worth quibbling about when survival is at stake, especially if you have to take off your gloves and boots to count with your digits. It's a more likely wind chill for circumpolar and northernmost areas.
An interesting tidbit was that with the -70F in ND and it being 92F in Miami at the same time there was a 162 degree temp difference in lower 48 states.