(NEW YORK) -- A heat wave stretching from coast to coast has claimed at least 11 lives.
Over 100 million Americans have been affected by heat alerts issued in more than two dozen states with heat indexes in the triple digits across the U.S.
A 12-year-old died in Phoenix, Arizona, after hiking in the triple-degree heat on Friday.
In Williamsport, Pennsylvania, a 4-year-old girl died Friday after being left for hours in a hot car as temperatures hit 97 degrees, police told ABC affiliate in Scranton WNEP-TV.
There were also five heat-related deaths this week in Roseville, Michigan, where temperatures soared into the high 80s and low 90s.
On Sunday, officials in Philadelphia said there were at least four heat-related deaths so far as the city prepared for the start of the Democratic National Convention. Protesters took to the streets, despite the heat, with extra water and medics on hand.
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