Maybe not in Arizona, but in the cold NE it's known about and currently very relevant. My last two operators applied it when operating in the US - and the USAF certainly do. I would be suprised if others don't.
Worth applying? The error is approx 4' per 1000' per degree of difference from ISA and should be applied below ISA -15. So if you have a MDH (H because it is relevant to your touchdown) 0f 500' and the OAT is -30, you should add 90' to your minima.
Significant I think.