Part of the Chicago area will be under an Excessive Heat Watch for multiple days this week as dangerous heat could bring heat index values as high as 108 degrees.
The watch, issued for Cook County, takes effect Thursday afternoon and continues through Saturday evening, with heat indices potentially peaking between 100 and 108 degrees each day.
Air temperatures are forecast to rise into the upper-90s and drop only to around 80 degrees in the city Thursday and Friday nights, offering "little to no relief from the heat," according to the National Weather Service.
"The cumulative effects of temperatures and heat index values this high could lead to heat related illnesses with prolonged exposure," the watch states. "Those without air conditioning, elderly, small children, and pets are especially susceptible. Plan ahead."
Residents are being urged to find a cool place to shelter from the heat and to avoid outdoor activity during peak heating times of the day.
Isolated storms are also possible each of those days, which could affect air temperatures, though the watch warns that dangerous heat could still expand into the area by Friday, with little to no relief from heat both Thursday and Friday nights.
The National Weather Service also said "the urban heat island core of Chicago is most susceptible to night time temperatures that do not cool significantly, limiting the amount of relief that can occur at night."
ComEd announced Tuesday that it is increasing crew staffing and opening its Emergency Operations Center to "respond quickly if power outages occur."
Anyone who experiences an outage is urged to test "OUT" to 26633 ot call (800) 334-7661. Spanish-speaking customers can call (800) 955 8237.
The city could see some relief Sunday, which looks to be partly sunny and not as hot with highs in the upper 80s. Still, humid conditions are expected with a chance of showers and storms.