Extreme Heat Warning

* WHAT...For the Heat Advisory, heat index values up to 104 expected. For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 109 expected.

* WHERE...Clarke, Frederick, Page, Shenandoah, and Warren Counties.

* WHEN...For the Heat Advisory, from 10 AM to 8 PM EDT Thursday. For the Extreme Heat Warning, from 10 AM to 8 PM EDT Friday.

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