* WHAT...Heat index values up to 100.
* WHERE...In Pennsylvania, Higher Elevations of Fayette, Higher Elevations of Westmoreland, and Higher Elevations of Indiana Counties. In West Virginia, Eastern Preston, Eastern Tucker, Preston, Ridges of Eastern Monongalia and Northwestern Preston, and Western Tucker Counties.
* WHEN...Until 10 PM EDT this evening.
* IMPACTS...Hot temperatures and high humidity may cause heat illnesses.