Savage Con-Dem cuts have forced nearly five times as many workers to turn to their union for financial help now than in 2010, Unison said yesterday.
The coalition's three-year pay freeze and other attacks on workers' incomes has caused a huge 388 per cent rise in the number of people asking Unison to help them pay the bills.
"Never in all my years in the union have I seen so many members struggling so hard just to keep warm and to put food on the table," said general secretary Dave Prentis.
Nurses, carers, cleaners and teaching assistants said that their wages were so stretched that they had to pick between eating and heating their homes.
And one in three said not being able to afford to turn the radiators on had hit the health of someone they live with - including people already suffering from cancer, bronchitis, MS, asthma and arthritis.
"It is heartbreaking to read some of the stories behind these requests for help," Mr Prentis said.
He said it was "disgraceful" that people should have to pick between food or heating.
"And is it any wonder when public service workers have been stuck on a three-year pay freeze, while prices just keep on going up?"
Unison said it wants urgent action to curb soaring fuel poverty, including measures to insulate Britain's homes and install energy-efficient central heating, which would create jobs and slash bills.