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.

Dangerous temperatures will persist across parts of the U.S. through July, and in some areas, there's an unexpected contributor.