A heat advisory is already in effect for some areas, including Pike and Gibson counties in Indiana, as well as Edwards, Wabash, and White counties in Illinois.
The National Weather Service says heat index values could reach up to 105 to 110 degrees in parts of southwest and west-central Indiana and southeast Illinois.
An advisory will go into effect starting Wednesday afternoon for Knox, Daviess, Martin, Greene, and Sullivan counties.
Health officials urge people to stay hydrated, limit outdoor activity, and check on vulnerable neighbors. Those working outside should take frequent breaks in the shade or in air-conditioned spaces. Heat stroke is a medical emergency—call 911 if symptoms appear.
The official forecast calls for sunny and hot conditions throughout the week, with daytime highs in the 90s. Overnight temperatures will remain clear with lows in the 70s.
The next chance for rain is Friday.
