WASHINGTON, July 13 (UPI) -- The death toll from a heat wave in much of the United States reached 39 as the National Weather Service issued warnings for 24 states, officials said Wednesday.
With an estimated 150 million people suffering from searing heat, temperature records across the country were either matched or exceeded at least 670 times since the beginning of July, ABC News reported Wednesday.
Oklahoma City experienced its 14th straight day of temperatures higher than 100 degrees Tuesday, while Phoenix has seen at least 33 consecutive days of temperatures at that level.
In Dallas, with 11 days at or above 100 degrees, city inspectors are going door-to-door to make sure air conditioners are working.
In Wisconsin, 15 runners were hospitalized after collapsing while competing in a half marathon.
Drinking plenty of water is the best line of defense to deal with the heat, medical experts said.
"When the heat goes up at this level, you could be going through a liter every hour. If you don't replace that, it could be very dangerous," ABC News' chief health and medical editor Dr. Richard Besser said.