A dangerous heat wave continues to scorch a large part of the United States, with more than 130 million people under extreme heat watches and warnings from South Dakota to Florida as temperatures in some cities are expected to exceed 100 degrees and heat indexes — or “feels like” temperatures — could soar past 115°F.

More than 250 million people in the U.S.—nearly three quarters of the population—are experiencing moderate, major or extreme risk of heat effects on July 28, according to the National Oceanic and Atmospheric Administration’s National Weather Service.