Carbon monoxide detectors are required to sound an alarm when concentrations are greater than 100 ppm. The time of exposure, the concentration of CO, the activity level of the person breathing the CO, and the person's age, sex, and general health all affect the danger level. For instance, a concentration of 800 ppm will cause headaches after one hour, but can lead to unconsciousness and death in 2 to 3 hours. Strong physical exertion, with an accompanying increase in the respiration rate, shortens the time to critical levels by 2 or 3 fold. Immediately move the person into fresh outside air and call for medical assistance.
Medical treatment depends on the amount of carbon monoxide in the bloodstream.
Often oxygen is administered. In severe cases, patients are treated in a pressurized oxygen chamber called a hyperbaric chamber which quickly and thoroughly forces the carbon monoxide from the body. Many hours, even days, may be required for carbon monoxide to be eliminated from the body unassisted. During this time, additional damage can occur. Yes, continued exposure to carbon monoxide can cause permanent brain, nerve, or heart damage.