Carbon monoxide, often shortened to CO, is a gas with no colour, no smell, and no taste. It forms when fuels such as gas, oil, kerosene, wood, charcoal, or petrol do not burn fully. Boilers, gas cookers, fires, stoves, water heaters, and portable generators can all produce it when they are faulty, blocked, or used in the wrong place. Because people cannot sense it, the main household protection is a working alarm.
Winter tends to bring more heating use, more closed windows, and more time indoors. A report from The Guardian published on 8 November 2026 describes a £40m scheme in England that aims to "keep most vulnerable people well at home" and avoid unnecessary hospital stays as the NHS prepares for winter pressure. The goal depends on many things, and a safe, well-ventilated home is one of them. This article looks at one small part of that picture: the alarms and heating equipment that many households rely on more in cold weather.
What the evidence shows, and where it is thin
Public health guidance on carbon monoxide is broadly consistent. Working alarms give early warning, and fuel-burning equipment should be installed correctly, serviced regularly, and kept well ventilated. What is less clear is how often alarms fail in ordinary homes, or how many households have working units, because the sources reviewed for this piece do not give a reliable national picture. Alarms also differ in design and lifespan, so the manufacturer's label and instructions are the best guide for any specific unit.
A seasonal alarm check
Start with the alarms. Choose a unit that carries a recognised safety standard mark for your country. Place one on every floor of the home, and near sleeping areas. Keep alarms away from cookers and steamy bathrooms, where normal cooking or humidity can affect them. Press the test button once a month, and note the date printed on the unit, since many alarms are designed to be replaced after a set number of years. If the unit uses a battery, replace it when the instructions say to.
Appliances and rooms
Before the first cold week, arrange for a qualified engineer to service gas boilers, fires, and cookers, as many national guidelines recommend. Ask the engineer to check the flue, which is the pipe that carries combustion gases out of the home, along with the air supply to the appliance and its built-in safety devices. Ask for the service report in writing and keep it with the alarm instructions.
Clear vents and flues of leaves, snow, nests, and dust. Keep the space around heaters free of curtains, laundry, and bedding. Never run a portable generator, barbecue, or charcoal burner inside a house, garage, shed, or porch. Do not leave a car running in an attached garage. If an unflued gas or paraffin heater is used, follow the instructions on how much fresh air the room needs, and open a window only as far as those instructions allow. A room that feels unusually stuffy, or a yellow or brown mark around an appliance, deserves a closer look from a professional.
When an alarm sounds
If an alarm goes off, leave the building, get into fresh air, and call the local emergency number from outside. Do not go back inside to look for the source. Anyone who feels unwell, with symptoms such as headache, dizziness, nausea, or confusion, should seek medical help promptly and mention that carbon monoxide may be involved. These symptoms are easy to mistake for a cold or the flu, which is one reason a working alarm matters more than guessing.
Making it a household routine
Pick a fixed date each autumn to run the seasonal check. Many families use the day the clocks change. Test each alarm, look at the service record, check the date on each unit, and walk through the plan with everyone in the home. Write the emergency steps on a card and keep it near the front door.
Readers comparing service options for heating and cooking equipment can start with coverage for home systems and appliances, then compare the engineer's checklist with the steps above. Relatives who help look after older or unwell family members can share the plan too, since a working alarm protects everyone in the home, not only the person who happens to notice the smell or the symptoms first.