We will hear the term "heat index" quite a bit this week.
A University of Illinois Extension climate change specialist explains what that really means.
The Extension's Duane Friend says the heat index is a measure of the actual temperature, combined with the relative humidity to provide a "feels like" temp.
"When we start getting into that type of "feels like" temperature, that's really where we start seeing issues with our bodies and not being able to get rid of that heat, which means our internal body temperature starts to increase and the more activity we do in those types of conditions our body temperature starts going up and that's when we can start getting into issues with heat exhaustion, heat stress."
Friend says the lesser known "Wet Bulb Globe Temperature" provides an even better read on how dangerous the heat is outside.
It's an indicator of the heat related stress on the human body in direct sunlight, and is used in marathons, other athletics and by the military.
