Nearly 20% of people suffering from cancer will have their recovery hampered by fuel poverty this winter, according to a charity.
In addition to the strain of cancer treatment, patients who cannot afford to switch the heating on will be forced to shiver away in their beds.
"Fuel poverty" is the term given to households that must spend at least 10% of the overall income on heating and lighting the home.
According to Macmillan Cancer Support, about 19% of patients having treatment fell into this category over the past year - which is twice the average of the UK population.
The charity called on the government to lengthen the winter fuel payment for this group, and has launched a campaign for sufferers undergoing treatment to have full access to mandatory social support offered by energy companies by 2011.
Macmillan's chief medical officer, Professor Jane Maher, said: "I see cancer patients suffering from exhaustion during and after treatment all the time.
"Add the factor of 'feeling cold' to exhaustion and you are left with seriously demotivated cancer patients that can do little other than go back to bed to stay warm and conserve energy."