* WHAT...TEMPERATURES 90 TO 100 FOR INLAND ORANGE COUNTY, 90 TO 102FOR THE SAN DIEGO COUNTY VALLEYS, 100 TO 108 FOR THE INLAND EMPIRE AND 89 TO 101 IN THE MOUNTAINS.

* WHERE...ORANGE COUNTY INLAND AREAS, RIVERSIDE COUNTY MOUNTAINS, SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE, SAN DIEGO COUNTY MOUNTAINS, SAN DIEGO COUNTY VALLEYS, AND SANTA ANA MOUNTAINS AND FOOTHILLS.

* WHEN...FOR THE HEAT ADVISORY, UNTIL 10 AM PDT TUESDAY. FOR THE EXTREME HEAT WATCH, FROM TUESDAY MORNING THROUGH FRIDAY EVENING.

* IMPACTS...HEAT RELATED ILLNESSES INCREASE SIGNIFICANTLY DURING EXTREME HEAT EVENTS. HOT TEMPERATURES MAY CAUSE HEAT ILLNESSES.

* ADDITIONAL DETAILS...LOW TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL WILL LIMIT RELIEF FROM THE HEAT. INCREASING TEMPERATURES INTO THE MIDDLE OF NEXT WEEK WILL INCREASE THE THREAT OF HEAT-RELATED ILLNESS ACROSS POPULATIONS.