The number of Lincolnshire households in fuel poverty will double over the next few years, said Colin Davie, of Lincolnshire County Council.
More than a quarter of all Lincolnshire households already spend at least 10% of their income on keeping warm, he told the council's environmental scrutiny committee on Friday (27 April).
Yet over £100m went unclaimed in benefits in Lincolnshire each year.
These benefits opened doors to government schemes designed to help tackle fuel poverty, like the Energy Company Obligation (ECO) due to be launched later this year,
The initiative is replacing the Carbon Emissions Reduction Target (CERT) and Community Energy Saving Programme (CESP).
Councillor Davie, who chairs the environmental scrutiny committee, said: "The problem of fuel poverty is exceptionally serious here in Lincolnshire.
"We face huge challenges, especially in the more rural and coastal areas where people are less likely to be connected to the main gas supply."
People who did not work, or those who had retired, didn't always have enough money to spend on essentials like keeping themselves warm, said councillor Davie.
"It's important we do all we can to help these residents in particular. Living in cold and damp conditions can have an impact on health, and lead to difficult choices to 'heat or eat'."
He added: "There is a national correlation between poorly heated homes, the vulnerable and excess winter deaths."
A special group was set up by the committee last September to contact different organisations and review how fuel poverty should be tackled.
Councillor Davie said: "What is crucial, for me, is finding ways to make sure people access the benefits they are fully entitled to - more than £100m is not claimed in Lincolnshire each year.
"This would go some way towards helping people stay warm and hopefully not worry so much, and also means they can access government schemes designed to tackle fuel poverty.
The standard of private sector housing also needed to be improved. "Older properties do have more solid walls, which are harder and more costly to insulate, but this does need to happen."
More than 14,000 households in Lincolnshire had benefited from the HELP scheme, which brings organisations together to reduce energy bills by insulating homes.
"We strongly believe that the HELP partnership has a greater role to play, co-ordinating activity between different organisations who are striving to make a difference to people's lives."
Recommendations from special group will be presented at the county council's executive committee in June for consideration and further action.