The arctic air will persist through at least Wednesday morning. Early Tuesday morning, wind chill readings ranged from -20 to -35 degrees, with colder wind chills for areas north and west of the city. With wind chills, this dangerously cold, frostbite, and hypothermia could happen on exposed skin within 30 minutes or less.

CHICAGO — National Weather Service officials issued a cold weather advisory in effect until 2 p.m. Tuesday for portions of central, east central and northeast Illinois as well as northwest Indiana. Officials said dangerously cold wind chills may reach as low as 28 below zero causing frostbite to those exposed to the frigid temperatures in as little as 30 minutes.