We have all felt the glow on our cheeks from sitting in front of a roaring fire.
Warm, cosy, comforting, it is understandable how demand for wood burning stoves soared in lockdown.
But scientists and campaigners are warning their popularity comes with huge environmental and health costs.
New research has found how burning wood at home is now a bigger source of fine particle pollution than road traffic. These tiny particles, no bigger than a strand of hair, are seen as extremely dangerous because they penetrate deep into the lungs and bloodstream, and enter other organs of the body.
Figures from the Department for Environment show that open fires and stoves cause 38% of this PM2.5 pollution – a figure that had doubled since 2003 to 41,000 tons a year. Road traffic is responsible for 12%.
Two-thirds of the people burning indoors use a stove, while a third have open fires, and 96% had alternative sources of heating such as gas or electricity.
The Government is not planning a ban on wood burners, but a ban on the sale of wet wood will come into force on May 1, as will a ban on bags of house coal, which produce more pollution.
But a Government survey showed a third of people who burn wood at home used waste wood or their own supplies. Burning waste wood or furniture is dangerous as it will have been treated with preservatives to kill wood worm, including arsenic.
Next year, new stoves will have to meet a standard called Eco Design that will reduce the levels of fine particles in the air. But campaigners say the Government should go further by banning wood burning in urban areas as it is a polluting luxury and not essential due to other forms of heating.
The Stove Industry Alliance, which represents manufacturers and wood suppliers, said that Defra had overestimated how much wood was burned.