* WHAT. Heat index values of 100 to 104 degrees are expected at times this week with variability each day due to clouds and scattered showers and storms. * WHERE. Portions of north central, northeast, and northwest Ohio and northwest Pennsylvania. * WHEN. Until 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. The prolonged nature of the heat may increase heat stress with time.

* WHAT. Prolonged dangerous hot conditions are likely. Heat index values ranging from 105 to 110 degrees are expected during the day. Little relief will be observed at night with temperatures ranging from 70 to 75 degrees. * WHERE. Beaver, Fayette, Washington, Allegheny, Butler, and Westmoreland Counties. * WHEN. Until 8 PM EDT Saturday. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. Heat index values ranging from 100 to 105 degrees during the day. * 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 Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

The Pennsylvania Department of Environmental Protection has issued a code ORANGE air quality alert for Thursday, including the greater Pittsburgh region, including Allegheny, Butler, Beaver, Armstrong, Washington, Westmoreland and Fayette counties. A code ORANGE air quality alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, the elderly, and people suffering from asthma, heart disease, or other lung diseases. The effects of air pollution can be minimized by avoiding outdoor exercise or strenuous activity. For more information on ground-level ozone and fine particles, visit http://www.airnow.gov and https://www.ahs.dep.pa.gov/AQPartnersWeb/