Health experts are calling on people to have their boilers, heaters and cookers checked in the hope of avoiding 50 deaths a year from carbon monoxide poisoning.
The Health Protection Agency (HPA) said all fossil fuel and wood-burning appliances should be checked by a registered engineer before the colder weather sets in.
Carbon monoxide poisoning is a significant risk in the winter months, and causes around 50 deaths each year in England and Wales.
Symptoms include headaches, drowsiness, dizziness, chest pains, nausea and vomiting. The poisoning can cause sudden collapse, loss of consciousness and death.
Around 4,000 people in England are estimated to attend A&E each year due to carbon monoxide poisoning.
Although many will not need admitting to hospital, long-term exposure to carbon monoxide gas can cause neurological problems, including difficulty concentrating.
The HPA's Dr John Cooper said: "Many of these deaths take place between November and February due to faulty fossil fuel and wood- burning appliances, and are therefore preventable.
"To lower the risk, people should ensure that their fossil fuel and wood-burning appliances are regularly checked by an appropriately registered engineer. The HPA recommends that people have these appliances and their flues checked before the start of winter.
"Rooms in which appliances are used must also be adequately ventilated."
The HPA also recommends that people fit a carbon monoxide alarm which meets European Standards EN 50291.