At a special meeting by the Minnesota Public Utilities Commission Tuesday, members were told February heating bills could be $400 more.

The addition charge isn’t expected to show up on customers’ bills until September and the cost would normally be spread over a 12-month period.

“This could be a very harmful pricing event for many people,” Ian Dobson, a representative for the Minnesota Attorney General’s Office, told the PUC. It’s never a good time for a big price hike, he said, but during a pandemic “is one of the worst times it could happen.”

Past due bills continue to mount as both CenterPoint Energy and Xcel Energy because of the coronavirus pandemic, the Star Tribune reported.

The state’s largest gas provider, CenterPoint, which has more than 870,000 customers, estimates that customers will face about $300 to $400 in additional gas charges.

Xcel Energy, Minnesota’s second-largest gas provider with about 475,000 customers, estimated an additional charge of $250 to $300.

The PUC voted to start a formal investigation into the gas price spike.