Brrrr! it's colder than on Mars

Arctic chill freezes large areas of US and Canada

A brutal chill held much of the United States and Canada in its grip, with a record-breaking cold snap bringing temperatures lower than on the surface of Mars.

Schools, businesses and government offices were closed on Tuesday. Water mains and household pipes froze. Planes were grounded, trains were halted and roads and sidewalks became ice rinks.