Carbon monoxide is an odorless, tasteless, colorless gas that can cause loss of consciousness and even death depending on the CO concentration and exposure time. It kills an average of 180 people every year. Prolonged exposure to lower levels of carbon monoxide gas can cause low energy and long-term heart damage. In the short term, carbon monoxide poisoning can cause headaches, vomiting, unconsciousness, and possible death, if the carbon monoxide concentration is high enough.