Extreme heat across the U.S. Southwest will build on Wednesday and is expected to last for several days. In Southern California, there are major fire and health concerns.

LOS ANGELES (AP) — A dangerous, multiday heat wave descended on much of California and the U.S. Southwest, with near-record temperatures expected along with a higher risk of wildfires.

A heat wave is supposed to hit Southern California this week, coupled with gusty winds. LA officials say they're prepared for the increased fire risk. The greatest risk areas are in the San Fernando Valley.

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.