* WHAT...Dangerously hot conditions with temperatures up to 100.

* WHERE...San Francisco Bay Shoreline, East Bay Interior Valleys, Santa Cruz Mountains, Santa Clara Valley...including San Jose, Eastern Santa Clara Hills, and the East Bay Hills.

* WHEN...Until 11 PM PDT Sunday.

* IMPACTS...Most individuals will be at risk for heat-related illnesses without effective cooling or adequate hydration, especially with prolonged outdoor exposure. Without effective cooling and/or adequate hydration, heat-related illnesses including heat stroke will be a risk to everyone.

* ADDITIONAL DETAILS...Major HeatRisk (level 3 of 4) in the valleys. Extreme HeatRisk (level 4 of 4) in the mountains.