Parts of America are facing temperatures colder than Antarctica this week, as a cold front sweeps through the upper midwest.

US officials are urging residents from northern states to stay inside as the deep freeze sets in across the county, bringing with it life-threatening conditions.

A blast of Arctic air from the polar vortex is causing temperatures to drop as low as -40C (-40F), and in some cases even colder.

Read below for our coverage of the weather on Wednesday, as it happened