In Houston, Texas, it was nearly -6 degrees Celsius, particularly cold temperatures for wildlife not adapted to such intense cold.
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This Thursday night frost had dramatic consequences for a colony of bats living under a bridge in the Texas city.
Hundreds of them fell from the structure, completely frozen.
The Waugh Street Bridge is a popular area spot for bat watching.
Luckily, the Humane Society was able to rescue 138 of the little beasts, channel KHOU11 reports.
The leader of the organization, Mary Warwick, is an expert on bats. She told Fox 26 that 99% of the bats were moving and appeared to still be alive despite the bitter cold.
An estimated 250,000 Mexican free-tail bats live on the Waugh Drive Bridge, less than two miles from downtown Houston.