Firefighters battling a growing wildfire near the Southern California coast got a small reprieve Friday night but were bracing for rising temperatures as an extreme heatwave threatened to roast the Southwest with triple-digit temperatures this weekend. The so-called Sherpa Fire — one of several active wildfires burning in 10 states on Saturday — more than tripled in size Friday in Santa Barbara County, and by Saturday afternoon and had scorched more than 7,811 acres, officials said.