Extreme Heat Warning

* WHAT...Dangerously hot conditions with high temperatures up to 110 expected. Overnight low temperatures will be mostly in the 70s.

* WHERE...San Bernardino and Riverside County Valleys-The Inland Empire.

* WHEN...Until 8 PM PDT Friday.

* 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 overnight relief from the heat. Increasing temperatures through Friday will increase the threat of heat-related illness across populations.