PHOTOS: Coldest morning in DECADES: Half the US wakes up to record freezing temperatures as polar vortex cripples America

POLAR VORTEXRecord-breaking cold weather took hold on Tuesday as 187million people across the U.S. braced themselves for the effects from a ‘polar vortex’ of frigid arctic air, the coldest in nearly two decades which swept from the Upper Midwest to the Southeast. LINK