- headaches or dizziness
- breathlessness
- nausea
- loss of consciousness
- tiredness
- pains in the chest or stomach
- erratic behaviour
- visual problems
You can also find further detailed information on the following links:
http://www.hse.gov.uk/gas/domestic/co.htm
http://www.nhs.uk/conditions/carbon-monoxide-poisoning/pages/introduction.aspx
http://www.hse.gov.uk/riddor/index.htm