At least 21 people have died in one of the worst cold snaps to hit the US Midwest in decades.
Ninety million people – a third of the US – have seen temperatures of -17C (0F) or below. Some 250 million Americans overall have experienced the “polar vortex” conditions.
Hospitals have been treating patients reporting frostbite as parts of the country ground to a halt.
Temperatures are expected to swing to above average over the weekend.
via BBC
