Twenty eight per cent of over 65s said their main concern for the coming cold months is ensuring they can heat their homes, the survey found.
Extrapolating the figures, Age UK said that the problem could affect as many as three million older people across the UK.
On Thursday, ScottishPower became the fourth of the ''big six'' suppliers to reveal energy price increases so far this month, following British Gas, SSE and npower.
The price hikes have prompted fuel poverty campaigners to call on the Government to act on the ''national crisis'' of cold homes.
The UK is second only to Estonia among European nations for the number of people who are struggling to pay their energy bills, according to research by the fuel poverty alliance Energy Bill Revolution released on Friday.
The Age UK poll, conducted on 1,100 over-65s, also found that more than half were concerned about the increasing costs of energy.
The survey, marked to launch Age UK's Spread the Warmth winter campaign, also found that many are in the dark when it comes to health problems associated with the cold.
Chilly temperatures not only increase the likelihood and severity of flu, chest infections and other respiratory problems but they also raise blood pressure, which puts people at greater risk of heart attacks and strokes, a spokeswoman said.
It said that 24,000 older people may not survive the cold weather.
"It's vital for older people to keep warm, both inside and outside their homes in the winter months," said Caroline Abrahams, charity director of Age UK.
"Being cold, even for just a short amount of time, can be very dangerous as it increases the risk of associated health problems and preventable deaths during the winter.
"Through our Spread the Warmth campaign, we are calling on everyone to recognise the importance of staying warm and well this winter, and to think about older friends, neighbours and relatives as the temperature drops.
"Local Age UKs are providing a range of services across the winter months and anyone with concerns can also call Age UK Advice free on 0800 169 65 65."
The charity's winter campaign offers a lifeline to many elderly people in need of help over winter including home visits, lunch clubs, winter benefit checks and a handyperson service.
Last week, health officials said that people should keep their homes warm, with living room temperatures of 21C (70F) and bedrooms and the rest of the house heated to 18C (65F).