Thousands of PG&E customers in the East Bay lost power early Tuesday, and while the cause of the outage is not yet clear, it seems likely related to strained power grids amid a heatwave — something that also led to an even larger outage that affected over 40,000 homes and businesses on Sunday. Late Monday evening a Flex Alert was issued statewide asking all residents to shut off all unnecessary lights, set air conditioners to 78 degrees or higher, and generally conserve power between the hours of 2 p.m. and 9 p.m.

The alerts, which call for voluntary power conservation, are issued by the California Independent System Operator or ISO, which oversees the state's electrical grid.

As NBC Bay Area reports, hours after the alert was issued, more than 3,800 PG&E customers in Fremont and 2,500 or more customers in Walnut Creek lost power. Other outages were reported in San Jose, Morgan Hill, and Benicia.

The current heatwave, which is expected to last through Thursday and possibly longer, may not seem that dramatic in San Francisco, where temperatures are just above normal and things are still pleasant. But with triple-digit temperatures persisting for multiple days elsewhere in the Bay Area, a meteorologist with PG&E is now saying this is the single most impactful heat event to hit the region since 2006, as ABC 7 reported.

Meanwhile, dangerous heat is gripping Southern California this week as well, thus the entire statewide grid is feeling the strain. Temperatures in the mountains around LA are expected to exceed 105 in some cases, as the LA Daily News reports. Also, a truck carrying almost 1,000 birds was found in Fresno with the suffering creatures inside, over two dozen of which were either already dead or subsequently died after sitting in 107-degree heat.

And I hope you already own a fan, because as ABC 7 notes, stores all over the Bay are running low on stock, if they have any left at all. Also, good luck finding an air conditioner repairman.