Carbon monoxide is one of the deadliest gases that you will encounter on a daily basis. While it isn’t harmful in small doses and over a short period of time, if you are in an enclosed space with this gas it could kill you in as little as 5 minutes. Short term exposure will cause headaches, dizziness, nausea and loss of consciousness. This is why it is so important to be careful not to get exposed to the gas, but there are many different sources of it right in your own home. One danger that exists is back-draft, where an under-pressure in your home will pull in exhaust from a chimney into your home causing carbon monoxide to enter. It could easily become a problem if your home is too air tight. One simple way to test for this is to use a smoke pencil which will show you what pressure inside your home is leading to. You can also check for excessive soot around your devices which would tell you that there is an issue.