When you feel there is not enough oxygen or feel drowsiness, dizziness, vomiting, there may be too many CO or carbon monoxide around you.
Carbon monoxide (CO) is a colourless and odourless gas. Because you can't see, taste or smell it, it can affect you or your family before you even know it's there. Even at low levels of exposure, carbon monoxide can cause serious health problems. CO is harmful because it will rapidly accumulate in the blood, depleting the ability of blood to carry oxygen.