Moderate Expected Likely Heat Advisory Heat Advisory issued September 1 at 9:54AM CDT until September 1 at 9:00PM CDT by NWS Chicago IL Sep 1, 12:00 PM → Sep 1, 9:00 PM WHAT: Peak heat indices of 100 to 105 degrees expected today andWednesday afternoon. WHERE: Boone, De Kalb, Lee, Ogle, Winnebago, Central Cook, DuPage,Kane, Lake IL, McHenry, and Northern Cook Counties. WHEN: Until 9 PM CDT this evening. IMPACTS: Hot temperatures and high humidity may cause heatillnesses. + Read More Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Updated: Sep 1, 10:14 AM Source: NWS Alert