Heat Advisory

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 113. For the Heat Advisory, heat index values up to 109 expected.

* WHERE...In Oklahoma, Greer, Harmon, Jackson, and Beckham Counties. In Texas, Foard, Hardeman, and Knox Counties.

* WHEN...For the Extreme Heat Warning, until 9 PM CDT this evening. For the Heat Advisory, from noon to 8 PM CDT Friday.

* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Hot temperatures and high humidity may cause heat illnesses.