City and suburban authorities had mere hours overnight to transition from cleanup after a line of powerful thunderstorms left thousands without power and wind-related damage in its wake to a heat wave that pushed heat indexes over 100 degrees. Just a half day removed from tornado sirens blaring across northern Illinois Monday evening as a supercell storm moved through the area, officials from Elgin to the city quickly switched gears, asking residents to reach out if their homes lack proper cooling, even as they removed downed tree limbs. The storm downed hundreds of trees, which directly led t…