* WHAT...Afternoon heat index values 105 to 109 through Wednesday.
* WHERE...Bibb, Blount, Cherokee, Chilton, Etowah, Fayette, Greene, Hale, Jefferson, Lamar, Marion, Pickens, Shelby, St. Clair, Sumter, Tuscaloosa, Walker, and Winston Counties.
* WHEN...Until 9 PM CDT Wednesday.
* IMPACTS...Hot temperatures and high humidity may cause heat illnesses.