SAN FRANCISCO (KRON) — The Bay Area is feeling the sizzling July heat wave this weekend, with a Heat Advisory already expanded to include the North Bay Valleys.

San Jose, Santa Rosa and Napa are also under the Heat Advisory.

But even more serious heat is scorching surrounding areas, where an Excessive Heat Warning is in effect until Sunday at 11 p.m. The toasty temperatures are forecasted to last through Sunday.

The purple areas in the map below are at risk of hitting triple-digit temperatures this weekend:

NWS excessive heat

Aside from the most coastal neighborhoods in the Bay Area, most places will reach mid 90s to low 100s – making officials concerned about residents getting heat-related sickness, or even death.

On Saturday at 9:00 p.m., a California ISO Flex Alert was lifted. With the extreme heat forecasted, California ISO was encouraging voluntary conservation to maintain a safe and reliable power grid.

The Flex Alert encouraged consumers to:

  • Set thermostats to 78 degrees or higher
  • Avoid using major appliances, like dish washers, washers and dryers
  • Turn off all unnecessary lights

Consumers were also encouraged to use fans for cooling and unplug unused electrical items.

The National Weather Service urges people to stay safe by keeping cool and hydrated.

Bay Area counties have opened up cooling centers where residents can get relief from the heat in air conditioned spaces.

Click here for cooling centers in Santa Clara County.

Contra Costa County is offering some libraries, county buildings and community centers as shelters from the heat. Click here for specific addresses and opening hours.

People who are staying home can keep their curtains drawn to keep the hot sunlight from raising indoor temperatures and utilize fans and cold water.

Additionally, a Spare the Air Alert has been issued for Saturday, July 10 due to smog.

To protect yourself and your family when the weather is very hot, follow the tips below:

●     Never leave anyone including children and pets in a parked car, even briefly. Temperatures in the car can become dangerous within a few minutes.

●     Use air-conditioning to cool down or go to an air-conditioned building such as a mall or movie theater. Check indoor mask requirements for the public space you will be visiting.

●     Drink plenty of fluids. Don’t wait until you’re thirsty to drink more fluids. Avoid alcohol, caffeine and sugary drinks. If your doctor generally limits the amount of fluid you drink or has you on water pills, ask how much you should drink while the weather is hot.

●     Beat the heat with cool showers and baths.

●     Stay out of the sun as much as possible.

●     When possible, avoid strenuous activity during the hottest part of the day (between 11 a.m. and 4 p.m.) and take regular breaks from physical activity.

●     Wear loose, lightweight, light-colored clothing to help keep cool.

●     Wear sunscreen and a ventilated hat (e.g., straw or mesh) when in the sun and even if it is cloudy.

●     Be aware that some medicines affect the body’s ability to sweat and stay cool, including antihistamines, antidepressants, over-the-counter sleeping pills, anti-diarrhea pills, beta blockers, anti-Parkinson’s drugs and psychiatric drugs. Do NOT stop taking medication unless instructed to do so by your doctor.

●     Check on your neighbors such as the elderly or those in poor health to see if they need assistance.