What: High temperatures 85 to 98 degrees.
Where: Riverside County Mountains and San Diego County Mountains.
When: From 10 AM Wednesday to 8 PM PDT Thursday.
Impacts: Hot temperatures may cause heat illnesses.
Additional Details: Widespread moderate HeatRisk. Hottest conditions will be 5000 ft in elevation and below.
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.