A heat advisory went into effect for nearly the entire Chicago area Friday as heat index values are expected to rise near 105 degrees through the weekend.
The heat advisory began at noon and will continue through 11 p.m. Saturday. Illinois counties under the advisory include McHenry, Lake, DeKalb, Kane, DuPage, LaSalle, Kendall, Grundy, Kankakee, Cook and Will. In Indiana, Lake, Porter, Newton and Jasper counties are also under the advisory.
The National Weather Service warns that hot temperatures and high humidity may cause heat illness to occur.
"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the alert states. "Young children and pets should never be left unattended in vehicles under any circumstances."
Other tips include doing strenuous activities in the early morning or evening hours if necessary, wearing lightweight and loose-fitting clothing when possible, frequent rests in shaded or air conditioned environments and knowing the signs of heat stroke and heat exhaustion.
Saturday grows even hotter than Friday with highs in the low to mid 90s and heat Index values between 100 and 107 degrees, according to the NBC 5 Storm Team.
Sunday will continue to be hot with highs between 85 and 0- degrees and heat index values near 100.
The day will also bring a chance for showers and storms in the morning hours, some possibly strong to severe. The storms will move from north to south across the Chicago area before ending.
Another chance for isolated storms will be possible in southern counties during the late afternoon and evening hours.