* WHAT. Dangerously hot conditions with heat index values up to 113 starting mainly mid to late morning on Tuesday. Until then, Heat Advisory conditions will be in effect for most areas. * WHERE. Portions of southwest Arkansas, north central and northwest Louisiana, and east and northeast Texas. * WHEN. Until 8 PM CDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. Heat index values up to 110. * WHERE. In Arkansas, Union, Columbia, Hempstead, Howard, Lafayette, Nevada, and Sevier Counties. In Louisiana, Ouachita and Union Parishes. In Oklahoma, McCurtain County. * WHEN. Until 8 PM CDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dangerously hot conditions with heat index values up to 113 starting mainly mid to late morning on Tuesday. Until then, Heat Advisory conditions will be in effect for most areas. * WHERE. Portions of southwest Arkansas, north central and northwest Louisiana, and east and northeast Texas. * WHEN. Until 8 PM CDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. Heat index values up to 107. * WHERE. Portions of central, southeast, southwest, and western Arkansas. * WHEN. Until 9 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. For the first Heat Advisory, heat index values up to 106. For the second Heat Advisory, heat index values up to 107 expected. * WHERE. Pike, Central and Eastern Montgomery County, Northern Montgomery County Higher Elevations, Northern Polk County Higher Elevations, Polk County Lower Elevations, Southeast Polk County Higher Elevations, and Southwest Montgomery County Higher Elevations Counties. * WHEN. For the first Heat Advisory, until 9 PM CDT this evening. For the second Heat Advisory, from 11 AM to 9 PM CDT Wednesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.