Frigid temperatures across Massachusetts this past week are bound to hit ratepayers in their wallets — and if the conditions persist, could limit how much savings Bay Staters feel from Gov. Maura Healey’s plan to cut utility bills this winter.

A brutally cold week in New England with temperatures plunging below zero across much of Massachusetts on Friday is driving up energy demand for natural gas and electricity as heating systems work harder and run longer to warm homes.

Those dynamics are running headfirst into Gov. Maura Healey’s energy affordability push. Healey announced in her annual State of the Commonwealth speech last week that her administration will spend $180 million to cover the costs of 15 percent of ratepayers’ electric bills in February and March.

The utilities have also agreed to defer during those months an additional 10 percent of electric bills and 10 percent of gas bills for collection later. Liberty Gas, which will be giving its customers a 10 percent break without recouping that money, is the lone exception.

The costs of heating homes is a perennial issue this time of year in cold-weather regions like New England, so the savings offered during some of the most expensive months for energy are real. But if consistently below-average temperatures drag deeper into the winter, the average ratepayer might still wind up with comparatively higher bills as their heating systems use more energy to warm homes. Other charges, like the state’s energy efficiency program known as Mass Save, could also rise since they are based on a ratepayer’s energy use.

“This was a national cold snap, which has caused natural gas prices to spike across the nation, and this has pulled everyone’s prices up,” said Kyle Murray, Massachusetts state director for the Acadia Center. “It’s not just a Massachusetts-specific problem for these months. And as a result of that, we’re going to see really high bills, unfortunately, regardless of what the governor does. This relief is certainly welcome, but I think there’s just limited additional tools that they could tap into for additional relief.”