Carbon monoxide intoxication continues to pose a differential diagnostic gnostic and therapeutic problem. I Since the symptoms presenting are often unspecific, the chances that the condition will be wrongly diagnosed, or the diagnosis delayed, are good, resulting in submaximal treatment. The measured COHb level in the blood frequently does not correlate with the symptoms, and, in particular, permits no prediction to be made about the likelihood of Inter neurological deficits. Hyperbaric oxygen therapy can rapidly eliminate the CO, and in comparison with the administration of normobaric oxygen is accociated with a significant lowering of both mortality and long-term morbidity. For all of these reasons, the indication for hyperbaric oxygen treatment should be established early on. When neurological symptoms are present, or transient loss of consciousness, and in pregnant victims, treatment with hyperbaric oxygen is indicated. Should the emergency physician receive onsite hints of CO poisoning (information from victim or witnesses) or see evidence of its possibility (smouldering fire in flat, victim in garage, etc), he/she should contact the medical rescue centre to request suitable means of ensuring transport of the victim under oxygen treatment (helicopter, emergency ambulance) to the nearest specialised treatment centre.