Some 12,000 lives a year have been saved since the introduction of the winter fuel payment, according to a leading OAP charity.
Age UK published research in the Journal of Public Health which it said showed the number of excess winter deaths - defined as deaths which would not have happened anyway - among people over 65 had fallen by 50% as a result of the energy benefit.
It comes after official figures showed the death rate in England and Wales was around a third higher than normal for this time of year, with 28,800 deaths registered in the fortnight ending January 23.
Millions of people born before July 1952 are entitled to between £100 and £300 tax-free to help pay heating bills during winter and the charity said it had made a "significant impact" since it was introduced in 1997.
"It really does help"
Professor James Goodwin, head of research at Age UK, said: "This new research provides us with the strongest indicator yet that the winter fuel payment really does help to reduce excess winter deaths among older people.
"We have always known that the winter fuel payment provides a vital cash boost to help people meet these increased heating costs - we now have evidence that suggests it can literally make the difference between life and death."
The majority of excess winter deaths are among older people the research also revealed that over the last 60 years 2.6 million people - the majority aged over 65 - have died unnecessarily because of the cold.
The charity estimates that the cost of cold homes to the NHS is around £1.36bn every year.
Earlier this month, the Office for National Statistics revealed the death rate in the middle two weeks in January had been 32% higher than the average for that period over the previous five years (21,859).
The ONS suggested that the flu virus and the cold snap could be to blame for the increased death rate.