A phenomenon called "corn sweat" could exacerbate the impacts of the extreme heat blanketing a large portion of the U.S., according to experts.

"Corn sweat" refers to the process known as evapotranspiration. Corn plants, like other plants, absorb water through their roots to be used for growth and photosynthesis. Any excess moisture is then released as vapor via tiny pores in their leaves called stomata into the atmosphere, according to crop intelligence firm Taranis.

In Iowa, corn pumps out "a staggering 49 to 56 billion gallons of water into the atmosphere each day" throughout the state, the National Weather Service said. That can add 5 to 10 degrees to the dew point, a measure of the humidity in the air, on a hot summer day.