Why is it a good idea to have a carbon monoxide detector in the home?

Carbon monoxide is a poisonous, odourless, tasteless, invisible gas. In the home it is formed from incomplete combustion from any flame-producing appliance. 

Carbon monoxide can harm you if you are exposed to high levels in a short period of time, or to lower levels over a long period of time. Low levels of carbon monoxide poisoning cause symptoms similar to those of the flu or a cold, including shortness of breath on mild exertion, mild headaches, and nausea. Higher levels of poisoning lead to dizziness, mental confusion, severe headaches, nausea, and fainting on mild exertion.

Carbon monoxide detectors are set to sound an alarm before the exposure to carbon monoxide would present a hazard to a healthy adult. 

Current legislation states that if you have installed a wood burning or multi-fuel stove a carbon monoxide alarm is required.