Charities say they are seeing people owing increasing levels of unpaid bills and charges to suppliers.
The total amount owed has reached a record £4.4bn, prompting plans from Ofgem to ensure energy companies write off some of that debt.
Up to £500m could be knocked off the total under plans that regulator Ofgem wants to take effect early next year.
Dhara Vyas, chief executive of Energy UK, which represents suppliers, anyone facing difficulties paying should contact their energy provider as soon as possible.
“We know that far too many people are struggling to pay for the energy they need to use,” she said.
But she added that suppliers could help with efficient appliances, tailoring the tariff to customers’ needs or ensuring people were on the correct benefits.
The government has hinted at extra cost-of-living support in the Budget on 26 November.
In the meantime, as the cold weather sets in, various tips are available to keep people warm while controlling costs, including clothing, insulation and heating rooms people are in rather than the whole home.