The EPA level of 9 ppm appears to be a reasonable limit in homes. Flu-like symptoms decrease while away from the house. Illness is present when gas appliances are in use. Excess moisture on the interior of windows. They should immediately be moved into fresh air and medical authorities consulted.
Treatment depends on the amount of carbon monoxide in the bloodstream and assessment of the patient.
Often oxygen is administered. In severe cases, patients are treated in a hyperbaric chamber. This is a pressurized oxygen chamber. The combination of oxygen and elevated pressure quickly and thoroughly forces carbon monoxide from the body. Following are the locations of hyperbaric chambers in Iowa.