PORTLAND, Ore. (AP) — Subfreezing temperatures blasting much of the U.S. have put millions of Americans at risk of potentially dangerous cold as winter storms have left four dead and continue to dump snow from coast to coast. The National Weather Service said Sunday that wind chills could plummet as low as minus 70 degrees in Montana and the Dakotas. An estimated 95 million Americans faced potential windy, frigid conditions with temperatures below zero even into northern Texas. A Wind Chill Advisory was in effect for all of southern Wisconsin including Dodge and Fond du Lac Counties until Wednesday morning.