CHICAGO (AP) -- Much of the Midwest is still doing what it can to adapt to the oppressive summer heat that has settled in.
More than 70 Detroit schools without air conditioning are closing this afternoon. A Veterans Affairs hospital in Fargo, N.D., had to reschedule more than 50 surgeries after cooling systems struggled to keep up with the weather.
The hot air blowing over the cooler waters of Lake Michigan has created a thick fog over many of Chicago's beaches. Lifeguards have had to turn away swimmers because they couldn't see past the water's edge.
Relief is on the way. Cooler air should start moving into the Plains states this weekend. And by Monday, temperatures will drop into the mid-80s in the north.
But cities in the East will could still be sweltering. The heat wave is moving eastward, with temperatures expected to reach 100 degrees in Washington by tomorrow.
Forecasters say the unusually hot conditions are caused by a heat "dome" -- the result of a huge area of high pressure that is compressing hot, moist air beneath it. The conditions could last as long as 10 days in some areas.