* WHAT. Heat index values up to 101. * WHERE. Central Pennsylvania. * WHEN. Until 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Maximum heat index values 100-102 Friday afternoon. Maximum heat index values 100-104 Saturday afternoon. * WHERE. Central Pennsylvania. * WHEN. Until 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause an increase in heat-related illnesses. * ADDITIONAL DETAILS. The risk of heat-related impacts is expected to reach its highest level over the weekend. The early arrival of the heat in the summer season, persistence of heat over multiple days, and very warm nights will be aggravating factors of overall heat stress.

* WHAT. Dangerously hot conditions with heat index values up to 105 possible. * WHERE. Portions of north central and western Maryland, northwest and western Virginia, and eastern West Virginia. * WHEN. From Saturday afternoon through Saturday evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS. Oppressive heat and humidity will overspread the area Saturday and last into Sunday. Little relief from the heat is expected Saturday night with low temperatures in lower to mid 70s, which will compound heat stress on those without air conditioning.