Air passengers in the US face another day of disruption due to the extreme cold weather.
More than 7,300 flights were delayed and 3,514 were cancelled on Sunday, according to the aviation tracking website Flightaware.com.
The website's live 'Misery Map' showed the highest numbers of cancellations and delays from Denver International Airport in Colorado and Chicago O'Hare International Airport in Illinois.
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.