To emphasize your point: I have experienced -30 F in Michigan and Minnesota.
But I have never felt the cold like I did in Alabama at +40 F and 70% Humidity. Work outside all day in that and, when you come in, it's a good hour in front of the fire to unchill your bones.
I was in FL a couple years ago in Jan and it was 45 and very windy, and cold like I’ve rarely experienced, even having grown up in NYS.
I don’t know why it felt so cold. It’s not like 45 is even bad, even with a wind. But that cold down there, that same temp that is easily tolerable up here, cut like a knife in FL.
We froze and we even had our winter jackets on, having had them from flying down, so we were definitely ready for it. And used to it.
Weird.