A First Alert Action has been issued for Saturday, July 22 due to life-threatening heat index values.
The combination of low-level moisture and soaring afternoon temperatures will cause the heat index to reach 107 to 113 degrees in most areas.
Over parts of southern Illinois, the heat index will reach between 113 and 118 at times. This can be deadly if precautions are not taken.
Areas near large corn fields can feel even hotter, closer to 120 degrees, as the sun evaporates moisture from the corn stalks adding even more low-level moisture.
The actual air temperatures will be between 96-100 degrees. This will make the inside of your car reach 140 degrees within one hour.
Please stay aware and make sure your children and pets are not left in your vehicle.
Remember, more people die from heat-related illness in the United States each year than all other weather phenomenon combined.
Download the First Alert weather app to carry your local forecast with you wherever you go.
Friday evening will be hot and muggy. The heat index will most likely stay at or slightly above 100 degrees until 9 p.m.
There will be a slight let up on Sunday, although the heat index could still approach 105 degrees on Sunday afternoon.
Copyright 2017 KFVS. All rights reserved.