"At least 10 die in killer storms including mom and 7 -year-old as maps show where polar vortex will move with temperatures set to plunge to -42.7C | "

https://www.dailymail.co.uk/news/article-14404945/die-killer-storms-polar-vortex-grips-Rockies-northern-Plains-temperatures-plunge.html 

"

Temperatures are predicted to dip as low as -42.7C (-45F) with wind chills down to 51 below Celsius (-60F) in northeastern Montana into Tuesday. Chicago alone could face temperatures between -28 and -34C (-20 to -30F) this week as a blizzard strikes the Windy City, according to USA Today. "