Carbon Monoxide Kills.
You can't see it, taste it, or smell it.
There have been a few occurrences recently of people suffering from carbon monoxide poisoning as a result of bringing lit barbecues into tents or caravans for warmth. Carbon monoxide (CO) is difficult to detect because it is colourless and has no taste or smell. People often don't realise that they are being overcome by fumes until it is too late. Further messages on carbon monoxide safety can be found on the Health and Safety Executive website - http://www.hse.gov.uk/gas - or on the CO-Awareness website - http://www.covictim.org/
For further information please see the leaflets linked below.