Scorching temperatures on the Fourth of July fueled wildfires in California, as warnings from meteorologists that the coming days could see dangerously hot weather.

With much of the country in the grip of a heat wave that is set to break records and make conditions dangerously hot, a large blaze near Yosemite National Park has triggered evacuations and forced hospital patients to shelter in place.

The French Fire, in Mariposa County, California, began Thursday. It was 20% contained by Friday…