Maybe you have to live in the Northeast — or even Southeast United States — to get the full effect. But right now, much of the country is struggling through brutally cold weather. It’s not uncommon to see temperatures down in the teens across much of the South. And record sub-zero temperatures in the North have many recalling the “polar vortex” of 2014.

Home heating bills will surely be climbing this month as the mercury plunges. But there’s a more troubling problem emerging. As Bloomberg News is reporting, the nation’s electric grid has begun to show signs of “fatigue” as power plants churn in overdrive to meet heavy demand. Oil burning power plants in New England are running short on fuel. And some of these plants may reach end-use limits due to emissions restrictions.