(Roger Kisby | The New York Times) Ashley Dehetre and Katelyn Price, walk on the salt flats of Badwater Basin in Death Valley, Calif., on July 10, 2021, after a 33-hour road trip from Detroit. Much of the West again faces record-breaking temperatures over the coming days, with over 31 million people in areas under either an excessive heat warning or a heat advisory. It is the third heat wave to sweep the region this summer.