Protesters have gathered outside Scottish Gas' headquarters in Edinburgh to campaign against rising profits while one in four people are living in fuel poverty.
James Granger, campaigner for Fuel Poverty Action, said many people are "being forced to make an impossible choice between heating and eating, while the profits of the big six energy companies just keep going up".
He said: "Scottish Gas, who are the Scottish arm of Centrica, are raking in record profits while the elderly, the disabled and cancer patients can't afford the heat they need to keep warm.
"That is leading to illnesses and deaths in the winter.
"As well as that, the Big Six energy companies like Scottish Gas, hand in hand with the government, are pushing ahead with what they call a 'dash for gas', but the rising cost of gas is the main reason why our bills are rising.
"What the dash for gas will mean is even higher fuel bills, and as well as that it's going to worsen climate change, which will mean rising fuel prices and flooding for many people in the UK.
"There is an alternative to that, which is clean renewable energy produced to the benefit of people, and not for energy fat cats and millionaire politicians."
Scottish Gas managing director Kevin Roxburgh said: "The safety of our people is our top priority.
"We will be ensuring that any activity is also safe for any protesters on our land. We recognise they have the right to make a peaceful protest.
"British Gas, parent of Scottish Gas, has helped over two million people in the last year with flexible payment plans and other direct financial support."