Some Chicago-area schools have announced closures or switches to e-learning for Tuesday as the region braces for dangerously cold wind chills. While many schools were already closed across the region for Martin Luther King Jr.

The core of the polar air will settle across the area Monday night into Tuesday morning, causing possible wind chills of -30.

Here's which schools are closed or on a delay as extreme cold continues Wednesday Students throughout the region were scheduled for a three-day weekend in honor of Martin Luther King Jr. Day on Monday,