CHICAGO (CBS) — One of the hottest days of the year was on tap for Monday, as temperatures were expected to reach a high of 92 degrees in Chicago, with heat indexes that could push past 105 in much of the Chicago area.

As of 6 a.m., it was already 79 degrees at Midway International Airport, although the official Chicago temperature at O’Hare International Airport was slightly cooler at 77 degrees.

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CBS 2 Meteorologist Megan Glaros reports the humidity was inordinately high Monday morning. As temperatures continue to rise throughout the day, past 90 degrees, the heat index could climb as high as 105 across most of the area, and up to 109 in the far southern and western suburbs.

Temperatures should reach about 90 degrees by noon, with a heat index of about 100.

The hot and muggy conditions have prompted Cook County officials to warn residents of an increased risk of heat-related stress and illness, particularly for very young children, the elderly, and anyone participating in strenuous activities outside.

Officials said people should stay indoors as much as possible, limit exposure to the sun, and drink plenty of water — but avoid caffeinated beverages or alcohol. People also should wear loose-fitting, lightweight, and light-colored clothing.

For those without air conditioning, many public buildings serve as cooling centers during the summer, including police stations and public libraries in Chicago. The city’s Department of Family & Support Services also operates six designated cooling centers:

Englewood Center
1140 W. 79th Street
Chicago, IL 60621

Garfield Center
10 S. Kedzie Ave.
Chicago, IL 60612

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King Center
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
4357 W. Armitage Ave.
Chicago, IL 60639

In the suburbs, most township offices serve as cooling centers.

Storms could fire up later in the day as a cold front approaches the region. None of the storm activity was expected to be significant, but some popup storms could hit parts of the area Monday afternoon and overnight.

Conditions on Tuesday will be only slightly cooler, with a high of about 88 degrees, and the heat index topping off around 97 degrees.

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The middle of the week should bring some relief from the heat, as temperatures on Wednesday should reach only about 78 degrees, and on Thursday the high should be only about 75 degrees.