Out-of-control wildfires in the foothills of a national forest east of Los Angeles and in a recreational area south of Reno, Nevada, threatened buildings and forced hundreds of residents to flee amid a days-long heat wave of triple-digit temperatures. In California, the so-called Line Fire was burning along the edge of the San Bernardino National Forest, about 65 miles (105 kilometers) east of Los Angeles. As of Monday morning, the blaze had charred about 32 square miles (83 square kilometers) of grass and chaparral and blanketed the area with a thick cloud of dark smoke.