Overnight temperatures will provide little relief from the sweltering daytime heat, dipping only into the mid-70s.

Heat advisory in effect until 8 PM EDT Wednesday for high temperatures across multiple regions, with heat index values up to ...

The advisory, which is expected to last from noon to 8 p.m., spans over several areas including Cook, Dekalb, McHenry and DuPage counties, according to the National Weather Service.