* WHAT...Very cold wind chills as low as 20 to 25 below zero expected.

* WHERE...Portions of central, east central, north central, and northeast Illinois and northwest Indiana.

* WHEN...From 6 PM CST /7 PM EST/ Sunday to noon CST /1 PM EST/ Monday.

* IMPACTS...The dangerously cold wind chills as low as 20 to 25 below zero could cause frostbite on exposed skin in as little as 30 minutes.

* ADDITIONAL DETAILS...After some recovery Monday afternoon, another round of dangerously cold wind chills is expected Monday night into Tuesday morning.