Carboxyhaemoglobin and methaemoglobin findings in burnt bodies

The often observed absence of carboxyhaemoglobin in burnt (charred) bodies is re-discussed in the light of two new cases in which the inhalation of very hot gases obviously led to reflex breathing and circulation arrest. (Macro and microscopic evaluations of the upper respiratory tract can give significant information as to whether a person was still alive at the time of the fire outbreak.) In the cadaver blood of people who survived a given period after a fire, high methaemoglobin values (up to 37%) were found. This was caused by the inhalation of nitrogen oxides that were produced by burning plastic.