The National Weather Service released an extreme cold warning at 12:56 p.m. on Thursday in effect until Friday at 11 a.m. for Carbon and Monroe counties. "The dangerously cold wind chills as low as 25 below zero could cause frostbite on exposed skin in as little as 30 minutes. Understanding cold weather alertsExtreme cold warning: Take Action! An extreme cold warning is issued when dangerously cold air temperatures or wind chill values are expected or occurring. A cold weather advisory is issued when seasonably cold air temperatures or wind chill values, but not extremely cold values, are expected or occurring.