* WHAT...Dangerously hot conditions with heat index values from 98 to 105.
* WHERE...Portions of central Upper and western Upper Michigan.
* WHEN...Until 10 PM EDT /9 PM CDT/ Tuesday.
* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
* ADDITIONAL DETAILS...Overnight low temperatures will range from 70 to 75 degrees, limiting recovery from heat.