A fire weather watch and red flag warnings have been issued for later this week across portions of Southern California. The National Weather Service has issued red flag warnings across large sections of Ventura and Los Angeles Counties, while a fire weather watch is also in place.

A red alert for extreme heat has been issued in Southern California and the state is braced for high temperatures.

Los Angeles — A dangerous heat wave descended on much of California and the U.S. Southwest, with triple-digit temperatures expected along with a higher risk of wildfires.

The report, released this week, found that 58% of fast-food workers surveyed in July said they had worked in excessive heat conditions in the last year. And nearly half, or 48%, reported experiencing heat illness symptoms including headaches, fatigue, dizziness, confusion, muscle pain or nausea.

The buildup is over; Wednesday is the day that triple-digit temperatures and dangerous fire conditions spread across much of Southern California. KTLA's Vera Jimenez and Kimberly Cheng report on Aug.