A polar vortex is currently hitting the United States, with schools closed in many areas and at least four deaths caused by treacherous conditions.

Most of the U.S. will enjoy milder temperatures on Thursday, but the warmup will be brief as a polar vortex will send temperatures tumbling below freezing for most of the nation starting this weekend.

Donald Trump announced the change to his plans on TruthSocial, pointing to a wind chill forecast by the National Weather Service forecasting 'severe record lows' on Monday.