Temperatures on the East Coast of the US have plummeted, with Chicago hitting lows of -15 this morning. The previous record for the Windy City was -14 in 1988.
NBC affiliate NBC Chicago tweeted a picture of Lake Michigan that appeared to show steam covering the Great Lake.
Chicago resident Jim Lakely posted a city-view picture that appeared to show the city's frozen river:
The anticipated 'polar vortex' is set to blast much of the country, with NBC reporting that "every state except Hawaii" is expected to face freezing temperatures today.
As much of the US experiences a dangerous and severe cold spell, does the UK have anything to worry about?
As the US battles sub-zero temperatures, ITV News Washington correspondent Robert Moore illustrates just how cold it is in Minnesota.
Leaders across America are urging residents to stay in their homes as "polar vortex" batters the east coast after snowstorm Hercules.