Heat Advisory

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the 90s to near 100 with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the mid 80s to low 90s expected.

* WHERE...Santa Ana Mountains and Foothills.

* WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday.

* IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses.

* ADDITIONAL DETAILS...Areas of Major HeatRisk. Very warm overnight temperatures will limit relief from the heat.