California firefighters worked in worsening heat Monday to contain a forest fire outside Yosemite National Park.
The Ferguson Fire had scorched nearly 53 square miles of timber and brush in the Sierra Nevada west of Yosemite and was just 13 percent contained.
More than 3,000 firefighters worked in difficult terrain, with little or no access to roads, while a fleet of aircraft assisted.
Weather conditions were worsening, meanwhile, as a heatwave grew in much of California under high pressure over the West.
The National Weather Service issued severe heat warnings Tuesday through Thursday as temperatures headed toward daytime highs in triple digits. Heat advisories were to go into effect Tuesday up the Central Coast and through the Central Valley into Oregon.