The stark choices faced by older people have been laid bare after an Age UK survey showed a third struggle just to buy basic supplies.
The charity said that if its study was projected nationally, it would equate to 4.5 million people aged over 60 who have to eke out their incomes.
Highlighting the "great resilience" of those on the breadline, its study - Living on a Low Income in Later Life - showed how people are forced to "make do", including going without basic household goods such as a television or an oven.
Living standards have been squeezed by the current low rate of returns on savings and rising household costs, particularly fuel bills.
The charity reported cases such as a 78-year-old woman living on £120 a week after rent who uses a hob and a microwave rather than replace a broken gas oven which she is concerned is leaking.
Other cost-saving examples found by researchers included boiling a kettle for washing rather than heating the water in a boiler, not replacing broken furniture and going without a television.
Age UK's study of more than 1,000 respondents found that nearly one in seven older people have gone to bed when they are not tired just to keep warm and around the same proportion said they live in just one room to save on heating.
Michelle Mitchell, charity director of Age UK, said: "Living on a low income is hard work. Currently there are 1.8 million people in later life living in poverty but our polling suggests that many above the official poverty line are finding life hard.
"Older people tend to show a great deal of resilience in managing their money and eke out their income, but this new report demonstrates exactly how emotionally draining it is for older people to constantly survive on a lower income and how many are fearful of the future in the current economic climate."
The report was compiled for the charity by Loughborough University using 25 in-depth interviews as well as focus group discussions and Age UK also based its research on a survey of 1,003 adults.
© 2012 Press Association