Corn sweat is exactly what it sounds like: moisture given off by corn. With large swaths of corn fields in the Midwest and even into Michigan, the amount of moisture in the air increases on hotter days.

The process is known as evapotranspiration, which is how plants, including corn, release water vapor into the atmosphere.

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