On Thursday, the National Weather Service warned people in the US Midwest that they should stay in as even five minutes of exposure could cause frostbite. The Midwest is in the grip of the Polar Vortex that has sent temperatures to record lows. “It’s just a dangerous cold,” said National Weather Service meteorologist Butch Dye. Temperatures are expected to rise by Friday but disruptions caused by the cold will persist, including power outages and cancelled flights and trains. Some nearby isolated areas could see temperatures as low as minus -40F (-40C).

Source: The Telegraph January 31, 2019 10:18 UTC