Forecasters at the National Weather Service in Indianapolis have upgraded the heat watch to an ‘excessive heat warning’ until 8 Saturday night.
Meteorologist Sonia Flechtner says the combination of oppressive heat and humidity led to the warning.
“The last time we had an excessive heat warning, it’s been a couple years, so this is fairly unusual for central Indiana,” she said.
Temperatures in the 90s coupled with high humidity will produce dangerous heat index values of around 105 to 110 degrees. Flechtner says it’s unusual for these conditions to hold steady for so long.
“We have a strong ridge of high pressure over the central plains, it’s just slowly going to move eastward into the Midwest pumping a lot of hot, moist air over the area and it’s going to stay that way until the early part of the weekend.”
The impact of heat stress increases each day the heat wave wears on. To reduce risk while doing outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned places.