SACRAMENTO, California — Swaths of California sweltered Tuesday and things were only expected to get worse during the Fourth of July holiday week for parts of the United States, with nearly 90 million people under heat alerts. The torrid conditions were being caused by a ridge of high pressure just off the West Coast and a separate ridge that spawned heat warnings and advisories from Kansas and Missouri to the Gulf Coast states, according to the National Weather Service. California’s capital, Sacramento, was under an excessive heat warning expected to last until Sunday night, with temperatures forecasted to reach between 105 degrees and 115 degrees. …About 70 miles north of Sacramento, crews working in scorching conditions were battling a wildfire in Butte County that forced the evacuation of about 13,000 people in and around Oroville. The governor’s office announced late Tuesday that federal funding had been approved to help with firefighting efforts.