Southern Californians headed to cool off at their favorite beach for the Fourth of July holiday as sizzling high temperatures arrive may have to avoid many popular spots for health reasons.

The public is advised to check local health maps before heading out to the beach for the holiday and the weekend after several tested positive for high bacteria levels, which may cause illness, according to Southern California county health departments.

The ocean waters at the Malibu Pier and the Santa Monica Pier are among many under a county health advisory after officials warned the public that bacteria levels are high in the area.

The Surfrider Beach at the Malibu Lagoon is also off-limits, as well as the Will Rogers State Beach at the Santa Monica Canyon Creek.

Three areas of the Marina Beach and Mother’s Beach in Venice, including the kayak area and playground, are also under the same health advisory. Venice is about 15 miles west of downtown Los Angeles.

Farther south near Long Beach, the ocean near the Cabrillo Beach boat launch and also has a high level of bacteria and the public is being asked to avoid it.

In Orange County, the Doheny State Beach at San Juan Creek south of Dana Point is under the same advisory for exceeding bacteria levels. Poche County Beach at the Poche Creek ocean interface north of San Clemente is also under state health advisory for the same reason.

In San Diego County, several beaches just north of the Mexican border at the Tijuana Slough are under advisory for exceeding bacteria levels.

An incoming heat wave coincides with the beach advisories, which are common in Southern California.

Most of California remains under an excessive heat warning issued by the National Weather Service this week.

Forecasters are expecting high temperatures to peak Thursday through Saturday. Desert regions should expect temperatures from 102 to 116, while mountain areas could see highs of 100 to 112.

In the valleys, temperatures are expected to reach 98 to 108 and coastal plains could see 94 degrees this week, according to the weather service.

Overnight low temperatures will remain warm, and fire risk will remain critical during the hot conditions and low humidity, forecasters reported.