CHICAGO (AP) — The swimming season has kicked into high gear early in a large swath of the U.S., as a heat wave pushed temperatures into the 90s and beyond in a stretch spanning from northern Florida to the Great Lakes and covering about a third of the country’s population. But the dangerously hot temperatures also prompted investigations into at least two deaths and authorities continued to advise people to take precautions while out in the heat for work or pleasure. The National Weather Service maintained an excessive heat warning through Wednesday evening for most of Illinois, Indiana and Ohio. The heat advisory in place for the Midwest and South stretched all the way eastward to the South Carolina shoreline.