Heat advisory issued for much of Bay Area Thursday, Friday

Temperatures are expected to soar across much of the Bay Area starting Thursday, prompting a heat advisory from the National Weather Service.

Highs will be in the 90s and 100s in most inland areas, and the advisory covers the Santa Clara Valley and its eastern hills, the interior East Bay, the North Bay interior mountains and the Santa Cruz Mountains, the weather service says.

The heat advisory takes effect at 10 a.m. Thursday and runs through 10 p.m. Friday.

The weather service warns the hot conditions can cause heat illnesses, especially to those sensitive to heat and those without effective cooling or adequate hydration.

Hydration is critical, the weather service says. Drink water and offer water to those who are vulnerable.

For those who need to be outside, wear lightweight and lo