* WHAT...For the first Heat Advisory, heat index values around 100. For the second Heat Advisory, heat index values between 100 and 104 expected. * WHERE...Portions of northern Indiana, southwest Michigan, and northwest Ohio. * WHEN...For the first Heat Advisory, until 8 PM EDT /7 PM CDT/ this evening. For the second Heat Advisory, from noon EDT /11 AM CDT/ to 8 PM EDT /7 PM CDT/ Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.