(Marcio Jose Sanchez | The Associated Press) A visitors shields herself with from the sun with an umbrella in the swimming beach at Castaic Lake on Saturday, Sept. 5, 2020, in Castaic, Calif. California is sweltering under a dangerous Labor Day weekend heat wave that was expected to spread triple-digit temperatures over much of the state while throngs of people might spread the coronavirus by packing beaches and mountains for relief.