* WHAT. Heat index values up to 105. * WHERE. Portions of central, northeast, northern and southern Maryland, The District of Columbia and central and northern Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur.

* WHAT. Heat index values up to 105 expected. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. Until 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

The Pennsylvania Department of Environmental Protection has issued a Code ORANGE Air Quality Alert on Tuesday for the Susquehanna Valley. A Code ORANGE Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases, and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors. For more information on ground-level ozone and fine particles, visit http://www.airnow.gov and http://www.aqpartners.state.pa.us.

* WHAT. Heat index values up to 104. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. Until 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 107 expected. * WHERE. In Delaware, Kent and Inland Sussex Counties. In Maryland, Caroline, Kent MD, Queen Annes, and Talbot Counties. * WHEN. From 10 AM Tuesday to 8 PM EDT Wednesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 104. * WHERE. Portions of northern Delaware, central, northern, and southern New Jersey, and southeast Pennsylvania. * WHEN. Until 8 PM EDT Wednesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 108 expected. * WHERE. Portions of central, north central and northern Maryland and central, northern and northwest Virginia. * WHEN. From noon to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Overnight conditions will remain warm and humid so continue to find ways to stay cool and hydrated.

* WHAT. For the first Heat Advisory, heat index values up to 105. For the second Heat Advisory, heat index values up to 107 expected. * WHERE. Portions of central, northeast, northern and southern Maryland, The District of Columbia and central and northern Virginia. * WHEN. For the first Heat Advisory, until 8 PM EDT this evening. For the second Heat Advisory, from noon to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Overnight conditions will remain warm and humid so continue to find ways to stay cool and hydrated.

The Pennsylvania Department of Environmental Protection has issued a Code ORANGE Air Quality Alert on Monday for the Susquehanna Valley. A Code ORANGE Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases, and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors. For more information on ground-level ozone and fine particles, visit http://www.airnow.gov and http://www.aqpartners.state.pa.us.