* WHAT...For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 105. For the Heat Advisory, heat index values up to 102 expected.
* WHERE...Portions of south central, southwest, and west central Illinois and central, east central, northeast, and southeast Missouri.
* WHEN...For the Extreme Heat Warning, until 10 PM CDT Friday. For the Heat Advisory, from 10 PM Friday to 8 PM CDT Saturday.
* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Hot temperatures and high humidity may cause heat illnesses.