* WHAT. Heat index values of 100 to 104 expected. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. In addition to the daytime heat, overnight low temperatures will also be very warm and oppressively muggy.

* WHAT. Heat index values of 100 to 104 expected. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. In addition to the daytime heat, overnight low temperatures will also be very warm and oppressively muggy.

* 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 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. Heat index values up to 103 expected. * WHERE. In Maryland, Washington County. In Virginia, Rockingham, Shenandoah, Frederick VA, Page, Warren and Clarke Counties. In West Virginia, Morgan, Berkeley and Jefferson Counties. * 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.

* 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.