Respondents to the charity’s survey also reported that worries about the cost of living and energy prices are leaving them without sleep (17%) and suffering poor mental health (28%).

The new research was commissioned as part of its Worried This Winter campaign, which aims to put a spotlight on the devastating impact of fuel poverty.

The figures show that:

• 33% of people in Scotland say their biggest financial concern this winter is their energy bills.
• 78% have cut back on some level of their expenses in the past year due to rising energy costs, with 24% limiting hot water usage such as bathing less regularly or sharing bathing water in an attempt to save energy in the last year.
• 59% have been wearing extra layers or using blankets rather than turning on the central heating in an attempt to stay warm in the last year.
• 28% have chosen not to switch on lights in their home when it is dark in an attempt to save energy.
• 36% say the cost of living and energy price have limited their ability to enjoy life, with 17% reporting they have lost sleep and 28% that it has affected their mental health.

The charity has been calling on both the UK government and the energy regulator to help struggling households by introducing lasting solutions such as a robust debt write-off scheme and an affordable social tariff that keeps bills down now and into the future.

CAS director of impact David Hilferty said: “As Scotland’s biggest advice charity, we see the reality of fuel poverty every day in the people who come to us for help. There’s been no let up for years now and the average debt we’ve seen across the last five years has doubled to £2,500.

“Being unable to afford energy bills is devastating for thousands across Scotland, forcing people into unimaginable circumstances.

“People are losing sleep, rationing hot water and not switching on the lights or heating, even when it’s cold and dark.

“This is shameful – people should simply not be living like this. It’s long past time that government and Ofgem stepped up their efforts to protect people on lower incomes and vulnerable circumstances during an energy crisis which shows no signs of abating. To do anything less amounts to a toleration of harm.”