Polar vortex: 12 dead as US weather system brings record low temperatures approaching -50F

The polar vortex in the US continued inflicting severe conditions across the country on Thursday, with temperatures reaching minus 40F - and a town in Michigan called Hell quite literally freezing over.Chicago was on track to break the city’s record of -32C (-26F), set more than 30 years ago as the cold snap intensifies.Some nearby isolated areas could see temperatures as low as -40C (-40F), that would break the Illinois record of minus 38C (-36.4F) set in 1999.