MOON TOWNSHIP – A strong winter weather system known as a polar vortex is sweeping across the country, sending temperatures in many cities plummeting to sub-arctic levels.

Schools and universities across the region have canceled classes on Wednesday in preparation for what could be one of the coldest days of the winter season. According to the National Weather Service, temperatures across western Pennsylvania will fall to a low of -1 degree on Wednesday.

Wind Chill Warnings/Advisories issued that start tonight and run through Thursday night/Friday morning. For details for your location, visit https://t.co/XcffZBrgkd, or https://t.co/JWLI3e1waM in your phone’s web browser! Also, check out https://t.co/acyua9mSFs for safety tips! pic.twitter.com/Spm2vnDCjX

— NWS Pittsburgh (@NWSPittsburgh) January 29, 2019

Wind chills across the region will fall to an even colder -20 degrees. Officials at the National Weather Service say that hypothermia and frostbite are a major concern.

Here are a few safety tips/reminders to deal with the extreme cold weather. #WinterSafety pic.twitter.com/9ydBCGejrQ

— NWS Pittsburgh (@NWSPittsburgh) January 29, 2019

Schools that have canceled classes altogether on Wednesday include:

• Avonworth School District
• California University of Pennsylvania (Jan. 30-31)
• Community College of Allegheny County
• Duquesne Univerity
• Moon Area School District
• Montour School District
• Pittsburgh Public Schools
• Point Park University
• Quaker Valley School District
• Robert Morris University
• Sewickley Academy
• University of Pittsburgh
• West Allegheny School District

Officials encourage residents to bring pets inside during the extreme cold. In a statement from Allegheny County, experts say to bring cats and dogs inside during the arctic freeze. Livestock should be moved to a sheltered area with non-frozen water and extra food.

This story is developing, stat with RMU Sentry Media for the latest updates.