As Chicago braces for dangerously cold temperatures, you may notice some changes in the weather advisories issued by the National Weather Service.

Chicago was waking up to a bitter cold morning Monday, with sub-zero temperatures and wind chills as low as -15. And it's only going to get colder from there.

Prepare for an Arctic blast as Chicago faces bitter cold overnight, with temperatures plummeting near zero and wind chills dipping as low as -25 degrees.