* WHAT...For the first Heat Advisory, heat index values up to 102. For the second Heat Advisory, heat index values up to 105 expected. * WHERE...Portions of central, east central, southeast, and west central Illinois. * WHEN...For the first Heat Advisory, until 7 PM CDT this evening. For the second Heat Advisory, from noon to 8 PM CDT Tuesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.