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

Minnesota and Iowa are known for their sultry summer days, with enough heat and humidity to go around. But why does it get so humid sometimes across the area? The answer is corn sweat.

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.