Chicago and the surrounding areas remain under a cold weather advisory as dangerously below zero wind chills could cause frostbite within 30 minutes of exposure.

Bundle up, Chicago, The first of two cold weather advisories this week was in effect for much of northeastern Illinois until 11 a.m. Monday morning, the National Weather Service said, with wind chill values or “feels like” temperatures as low as 20 to 25 degrees below zero.

A cold weather advisory is in effect until noon Tuesday, with wind chills ranging between minus 15 and minus 25 before plummeting to minus 10 overnight in outlying areas.