Presently, to make the diagnosis, the investigators possess the analysis of the blood HbCO by realization of gas of the venous blood, which are taken in emergencies, but very often a few hours after the end of the exposure at the source of poisoning, what is translated by a disappearance of the symptoms and an underestimate of the initial blood HbCO. Since 2005, MASIMO laboratory commercialize a pulse carboxymètre, the RAD 57, which allows to estimate the carboxyhémoglobinémie in a not invasive way.