 Authorities are warning about elevated risk of wildfires and worsened air quality with the soaring temperatures. Strong forecasted winds have also prompted Pacific Gas and Electric, the state's largest utility, to warn it may preemptively shut off power for some customers in northern California to avoid starting wildfires. Extreme heat is the deadliest weather event. Health officials are urging people to be aware of the conditions through the holiday weekend. Nathan Rott, NPR News.