Much of North America is in the grip of extremely low temperatures.
Cold air has rushed in from the Arctic, after a high pressure over northeast Canada and Greenland blocked the usual track of the weather.
At this time of year the Arctic sees 24 hours of darkness, and cold air festers over the region.
Strong winds circulate around the pole, trapping the cold air in place and creating what’s known as a ‘polar vortex’ a swirling mass of cold air, which rotates anti-clockwise around the Arctic.
This year, the usual path of polar vortex has been disrupted, sending a blast of cold air into North America.
Weather this severe hasn’t been seen in the region since 1994.
Residents are being urged to stay indoors, with meteorologists warning that temperatures this low can be life-threatening, and severe frost bite can set in within ten minutes.