CHICAGO (WLS) --The Chicago area is bracing for a potentially dangerous combination of hot temperatures and high humidity on Thursday and Friday, which could be the hottest weather in area since 2012.
The National Weather Service issued an Excessive Heat Watch for all of northern Illinois that remains in effect from noon Thursday to 7 p.m. Friday.
ABC7 Meteorologist Tracy Butler forecasts high temperatures in the low-to-mid 90s on Thursday and the mid-to-high 90s on Friday. Heat indices on both days will exceed 100 degrees, with a maximum of 115 degrees.
"Those heat index readings in the triple digits are certainly how it's going to feel," Butler said. "It's something we're really keeping a close eye on."
As Chicago area residents brace for the heat, technicians for Four Seasons Heating and Air Conditioning are in hot demand as customers hope to get services before temperatures get even hotter later this week.
"We're getting a lot of calls from all over the city," said Randy Szymenak, of Four Seasons, on Tuesday.
Counties under the Excessive Heat Watch include Cook, Will, DuPage, Lake, McHenry, Kane, Kankakee, Grundy, Kendall, LaSalle, DeKalb, Iroquois, Ford, Livingston, Winnebago, Boone, Ogle and Lee.
Residents are urged to plan ahead, have a cool place to take shelter, avoid outdoor activity during the afternoon, drink plenty of fluids and check on relatives and neighbors.
Metra is already warning riders that there could be delays due to the heat later this week. Any time temperatures exceed 95 degrees, Metra said it may be necessary for trains to reduce speeds to compensate for heat-related stress on tracks and signals. The slower speeds could mean delays up to 10-15 minutes, Metra said.
Watch the latest forecast from the First Alert Weather Team:
Cooling centers are open across Cook County, and the City of Chicago also operates six cooling centers during the summer months. The Garfield Center, located at 10 S. Kedzie, is available 24 hours a day, seven days a week to connect residents to emergency shelter.
The following cooling centers are open from 9 a.m. to 5 p.m. Monday through Friday:
1140 W. 79th Street
Chicago, IL 60621
10 S. Kedzie Ave.
Chicago, IL 60612
4314 S. Cottage Grove
Chicago, IL 60653
North Area Center
845 W. Wilson Ave.
Chicago, IL 60640
South Chicago Center
8650 S. Commercial Ave.
Chicago, IL 60617
Trina Davila Center
4312 W. North Ave.
Chicago, IL 60639
FULL LIST: Cook County cooling centers