Carbon monoxide: what is it and why is it deadly?

Many of us are familiar with the typical results of burning fuels such as coal, natural gas and oil. The reaction produces heat which we harness to warm our homes, heat water and cook food, power vehicles and generate electricity.

Combustion also produces gases, most obviously carbon dioxide. This is produced when the carbon, locked away in the petrol, gas or wood, reacts with oxygen in the air. We can't see or s