Carbon Monoxide (CO) is known as the Silent Killer because it is an odourless, tasteless and colourless toxic gas which is produced by incomplete combustion of fossil fuels used in central heating systems, gas appliances and fires. CO can be emitted from any appliance burning combustible fuel, e.g. gas (mains or bottled), solid fuel (coal, wood, etc), petrol, oil or paraffin etc.
In Katie’s case CO proved fatal but can also poison in tiny amounts because it is taken up in preference to oxygen by the haemoglobin (the oxygen carrying part) in the blood. Low-level exposure of CO over a long period can cause brain and neurological damage. Some people, particularly the elderly, are ill for months and even years without knowing why.
Some of the symptoms of mild carbon monoxide poisoning are headaches, dizziness, sore throat, dry cough and nausea, all of which could easily be confused with viral cold and flu infections, food poisoning or general tiredness.