Carbon Monoxide
Remember the good old days when you had the time to just sit and watch a fire. After a time you would become relaxed and drowsy and drift off to sleep. Sure, it's possible that it was simply the hypnotic effect of the dancing flames but it is more probable that it was a small dose of carbon monoxide from the burning logs. You suffered no ill effects because most  of the gas went up the chimney but at higher levels you would go to sleep and never wake up.

This is really important information so please read the following:

Carbon Monoxide is produced by the incomplete combustion of the fossil fuels - gas, oil, coal and wood used in boilers, engines, oil burners, gas fires, water heaters, solid fuel appliances and open fires.

Dangerous amounts of CO can accumulate when as a result of poor installation, poor maintenance, failure or damage to an appliance in service, the fuel is not burned properly, or when rooms are poorly ventilated and the Carbon Monoxide is unable to escape.

Having no smell, taste or colour, in today's world of improved insulation and double glazing it has become increasingly important to have good ventilation, maintain all appliances regularly and to have absolutely reliable detector alarms installed giving both a visual and audible warning immediately there is a build up of CO to dangerous levels.

NO SMELL and NO TASTE and NO COLOUR

And it is for these reasons that CO detectors are the only way to alert you to increasingly dangerous levels of CO before tragedy strikes.

What are the effects of carbon monoxide?

Carbon Monoxide produces the following physiological effects on people exposed to the concentrations shown:

Concentration of CO in air

Inhalation time and toxic developed

50 parts per million (ppm)

Safety level as specified by the Health and Safety Executive

200 PPM

Slight headache within 2-3 hours

400 PPM

Frontal headache within 1-2 hours, becoming widespread in 3 hours

800 PPM

Dizziness, nausea, convulsions within 45 minutes, insensible in 2 hours

Carbon Monoxide poisons by entering the lungs via the normal breathing mechanism and displacing oxygen from the bloodstream. Interruption of the normal supply of oxygen puts at risk the functions of the heart, brain and other vital functions of the body.

The above information is for a healthy adult. Persons suffering from heart or respiratory health problems, infants and small children, unborn children, expectant mothers and pets can be affected by CO poisoning more quickly than others in the household and may be the first to show symptoms."
http://www.carbonmonoxidekills.com/coinformation.htm

The above warning cannot be overstated. Failure to properly  maintain a fossil fuel heating system can result in the death of you or your family. Improper use of heaters using kerosene or other fossil fuels can result in the death of your or your family. Please take us seriously on this, be careful and make sure you have a properly operating carbon monoxide detector near your bedrooms regardless of the age of your home.