A person in South Yorkshire suffered carbon monoxide poisoning after burning coal in a tin bucket in their living room.
Firefighters have warned people struggling with energy bills not to resort to makeshift heat sources after call-outs to people starting “cost of living fires” went up.
Area manager, Matt Gillatt, said: “We know times are tough for lots of people right now, but the pattern we are seeing around unsafe heating in homes is concerning.
“Our ask is that people ensure they save safely.”
Gillatt said alternative heat sources, such as tin buckets or small gas cylinders, are not safe.
“Extra care” was needed when using log burners or electric blankets, he added.
The service is advising residents to make sure smoke and carbon monoxide alarms are fitted and working.
The warning comes as more than 60 charities have written to Prime Minister Rishi Sunak to demand more support for millions of UK households in fuel poverty.
A survey for the End Fuel Poverty Coalition claims 76 per cent of people think the Government is not doing enough to support vulnerable households this winter.
The poll says 58 per cent believe they will struggle to pay their bills this winter.
The letter, coordinated by the Warm This Winter campaign, is calling for benefits to be uprated with inflation and clarification of what support for energy bills will be available from April.