Using a pulse co-oximeter, a paramedic establishes that the blood of an on-duty fire fighter contains carboxyhemoglobin at a concentration of 55,000 ppm by volume. what would be the symptoms?

Well,i think the answer would be : no symptoms
Symptom is a physical or mental feature that is used as an indicator for the existence of a disease (such as rash, fever, etc)
Those above are simply laboratory facts/data, not symptoms

Awould be the most dangerous