* WHAT...Dangerously hot conditions with heat index values from 103 to 110.
* WHERE...Portions of northern Indiana, southwest Michigan, and northwest Ohio.
* WHEN...Until 8 PM EDT /7 PM CDT/ Thursday.
* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
* ADDITIONAL DETAILS...Peak afternoon heat indices around 100 degrees may extend into Friday.