ComEd officials say they're on high alert as a scorching heat wave moves in that will keep temperatures in the 90s or above this week.
The utility says service has been restored for nearly all of the hundreds of thousands customers who lost power following a storm in northern Illinois last week.
The storm knocked out service for about 850,000 customers on Monday. Crews have spent days clearing trees and restoring power since then. Suburbs north of the city were the hardest hit.
ComEd officials say the cost of restoration topped $80 million.
ComEd spokesman Tony Hernandez on Sunday said the utility will keep its emergency operations center open with a heat wave predicted this week.
The National Weather Service on Sunday issued heat advisories, warnings and watches for counties statewide.
Temperatures will climb into the 90s, and the heat index may reach 100 degrees and higher in some areas. Nightfall won't bring much of a reprieve as temperatures hover in the 70s at night.
The high temperatures could remain in the area through Friday.