Three Things You Didn’t Know About The Polar Vortex

1) Frost quakes have been reported in Ohio and here in Pennsylvania. They’re caused when large amounts of snow and rain settle into the earth, then a rapid plunge in temperature causes the newly-formed ice to expand.

Frost quakes sound like a boom or a bang – and then your house shakes.

2) Transit workers in Chicago have been setting commuter train tracks ablaze, trying to keep the steel from freezing so trains can keep moving. The fire also prevents switches from freezing.

3) Residents in at least 10 U.S. States didn’t receive their mail on Wednesday due to the record-breaking cold.

It’s not the first time that the U.S. Postal Service has cancelled mail delivery due to weather, but typically that has only happened due to massive amounts of snow on the roads.