More than 15 million UK households plan to ration their energy use this winter to cope with "sky-high" energy costs, according to uSwitch.
The price comparison website, which surveyed 5,300 people, found that almost six in ten (57%) people have already cut back or plan to ration their energy use this winter in a bid to reduce bills.
The research also revealed that more than a third of people (36%) who rationed their energy last winter said it affected their health and wellbeing.
"In this day and age it's shocking to see so many being forced to go without heating and risk their health, simply to cope with high energy bills," said Ann Robinson, director of consumer policy at uSwitch.
"Wholesale energy prices have been falling for a long time now and it's high time for the big six suppliers to pass on these reductions to hard-pressed consumers, who will be going cold because they simply can't afford to keep the heating on.
"Consumers do have a choice, however, and can take control of their energy.
"Making sure that your home is insulated, draught-proof and taking small actions like making sure appliances aren't left on standby, are all simple ways to use less and waste less energy."
The average UK home is set to spend £1,265 ($2,022, €1,616) on energy over the course of this year – £53 more than last year and £271 more than three years ago, according to the report.
Despite the fact that a number of new deals have recently launched for under £1,000, more than half (62%) of consumers expect that energy prices will continue to rise.
The charity, which surveyed more than 6,000 people that used its Energy Best Deal service, found that 78% of respondents said that they were concerned about the cost of their winter fuel bills.