10 Things to Know About California's Long Heat Wave

Updated Thursday, 1:30 p.m.

Where it's hottest: Triple digits have appeared just where experience and forecasts told us they would: the East Bay valleys, eastern Contra Costa County, the Napa Valley, and parts of the South Bay. Inland areas around the region are not far behind, with temperatures in the mid- to upper 90s reported from dozens of locations.

But where it's really hot is: Nearly the entire Central Valley, from red-faced Redding to broiling Bakersfield, is reporting temperatures well above 100. Of note: 109 in Bakersfield (forecast high: 109), 107 in Delano (Kern County; forecast high 109), 106 in Red Bluff (forecast: 113).

And then ... there's Death Valley: The 1 p.m. high at the Furnace Creek visitors center in Death Valley National Park was 117. The forecast there: 121, with an only slightly more unreasonable 124 expected in the park's Badwater area.

Where it's coolest: If you're looking for a break from the torrid conditions described above, the region's coolest weather continue to linger along the coast, with actually tolerable conditions in many locations along the bay shore.

When will it end? The National Weather Service still says it expects Thursday to be the hottest day in the Bay Area, with gradual cooling to begin Friday. The Central Valley could be in for an extra day or two of suffering, with forecasters extending an excessive heat warning through late Saturday.

Heat deaths reported: Santa Clara County officials reported two deaths related to the prolonged series of unusually hot days. The medical examiner's office identified those who succumbed as Dennis Young, 72, reported to be a homeless man found dead in a car, and 87-year-old Setsu Jordan, reported to have died outdoors.

Medical Examiner Michelle Jorden said in a statement: "It is tragic when someone dies of hyperthermia since in most every case it could have been prevented. Hyperthermia and heat stress happen when a body’s heat-regulation system cannot handle the heat. It can happen to anyone, which it is why it is so important to be in a cool location, drink plenty of water and take a cool bath or shower if you are getting too hot.”

The county's Public Health Department reiterated safety advice that's been widely publicized by the National Weather Service and other agencies -- emphasizing the vulnerability of infants, children and people over 65.

Safety measures: The National Weather Service heat warning and advisories include advice on how to respond to exposure to hot weather. Below: the NWS Bay Area's description of the range of heat risks.

Power outages: PG&E reported Thursday afternoon that about 1,300 customers were without power across its service area, which covers the northern two-thirds of California. The largest single outage was reported in San Francisco where 367 customers were reported without power in Pacific Heights.

Your rapidly melting snowpack: The San Francisco Chronicle has a good piece today on the high runoff levels resulting from the heat's effect on the bounteous Sierra Nevada snowpack. Some major rivers are running at double or triple their normal levels for this time of year.

"Heat storm": A PG&E spokesperson said earlier the utility prepares for extremely hot weather the same way it gets ready for a big, disruptive winter storm. She added that the current siege of very hot weather is "the most impactful event we've seen since the 2006 heat storm."

If we had heard the term "heat storm" before, we had forgotten it. What PG&E and others in the power industry are referring to is a 12-day siege of hot weather -- including 10 straight days of 100-degree heat in the Central Valley -- that fried transformers and, at some point or other, knocked out power to about 2.4 million of the state's 11 million electricity customers.

Both PG&E and the state as a whole hit their all-time electricity demand during the event. Statewide, the heat reportedly killed at least 130 people, including 29 in Stanislaus County and 27 in Fresno County.