* WHAT...For the first Heat Advisory, heat index values up to 107. For the second Heat Advisory, heat index values up to 108 expected. * WHERE...Pontotoc, Atoka, Bryan, Coal, Hughes, Johnston, Marshall, Carter, and Love Counties. * WHEN...For the first Heat Advisory, until 7 PM CDT this evening. For the second Heat Advisory, from noon to 7 PM CDT Thursday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.