* WHAT. Dangerously hot conditions with heat index values up to 105. * WHERE. Beaver, Fayette, Washington, Allegheny, Butler, and Westmoreland Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. Heat index values 95 to 100. * WHERE. Portions of east central Ohio, northwest, southwest, and western Pennsylvania, and northern and the northern panhandle of West Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dangerously hot conditions with heat index values up to 105. * WHERE. Beaver, Fayette, Washington, Allegheny, Butler, and Westmoreland Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. Heat index values 95 to 100. * WHERE. Portions of east central Ohio, northwest, southwest, and western Pennsylvania, and northern and the northern panhandle of West Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. Although afternoon thunderstorms have provided cooling relief across many parts of the region, a return to hot and humid conditions will again return on Tuesday and continue throughout the week.

* WHAT. Peak heat index values around 100 degrees expected this afternoon. * WHERE. Portions of north central, northeast, and northwest Ohio and northwest Pennsylvania. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. The prolonged nature of the heat may increase heat stress with time.