High temperatures combined with humid conditions to push the heat index way up in Iowa Monday. Temperatures could climb into the same range in parts of Iowa today (Tuesday).

Chuck Myers of the National Weather Service says the heat index is an important summer measurement — kind of like the wind chill in the winter. He says the heat index is a way to approximate how the heat and humidity together affect the human body. Myers says the dry conditions earlier this year kept the heat index from going up — but he says recent rains added water to the equation.

Myers says once the dew points gets about 65 to 66 degrees, the human body has to exert more energy to cool itself, and that makes you feel more hot. Myers says the National Weather Service issues a heat advisory once the heat index gets to 105 — which is the first sign you should take precautions.

Myers says once the index gets above 110 to 115, your body can have a fairly rapid response and go into heat exhaustion or heat stroke. Myers says if you’ve been outside you’ll likely be able to handle the heat better. Myers says you need to be in tune to the amount of heat your body can handle.