Energy Secretary Rick Perry warned Thursday that a polar vortex descending on the U.S. in the first half of March will be a major test for the nation’s electricity grid from Montana all the way to his home state of Texas.

“This is going to be a really deep, deep polar vortex all the way to my home state that will put a massive test upon our ability to deliver an energy supply to keep our citizens safe,” Perry said at a press conference.