Four out of ten people are worried they cannot afford their next energy bill, according to new research.
Citizens Advice (CA), which commissioned the report, said it helped clients with over 96,000 fuel debt problems last year.
The charity also found that one in three people do not know that energy companies are offering support to insulate homes.
It released the findings at the start of its Big Energy Week which aims to help people save money on their bills.
CA chief executive Gillian Guy said: "We know hikes in prices have put extra pressure on people's budgets at a time when money is already tight. Day in day out our bureaux help people who can't afford their fuel bills.
"We're worried that some people are struggling unnecessarily because they're not on the best deal, live in homes that haemorrhage heat or are not getting all of the financial help available to them."
CA said households could make annual savings of up to £200 on their energy bills if they look for a different supplier.
The study found that 43% of people are worried that they cannot afford their next fuel bill while one in two say energy bills will put a strain on their finances this year.
Energy Secretary Chris Huhne said: "We know that a lot of households are struggling to cope with rising energy costs. Many people could cut their gas and electricity bills by moving to a better deal with their existing supplier, switching to another supplier altogether, or by taking up home insulation offers.
"But we need to make sure consumers are aware of this and make it easier for them to take action to save money."
