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

The combination of corn sweat, the exhalation of water vapor through leaves, and a heat dome is bringing dangerously hot conditions to millions of people.

It’s not that corn sweats more than other plants — an acre releases less moisture on average than, say, a large oak tree — but the Midwest has a lot of corn in late July. In Iowa, for example, more than two-thirds of the area is farmland, and corn is the top crop (followed by soybeans, which, by the way, also sweat).