Meticulous screening and preparation of air travellers with known ailments would prevent most in flight emergencies if passengers at risk sought a medical opinion about their suitability for travel.1 In the absence of declared symptoms, however, the prediction of a potentially fatal condition at altitude is difficult if not impossible in a young patient apparently fit to fly. A useful review of the particular medical risks to be considered before travel by air is provided by Skjenna.1

Medical emergencies among airline passengers and staff during flight are not common: serious in flight events occur once in every 753 flights (about 1 per 40000 passengers).2 In 1994 British Airways health services logged all 2078 medical incidents occurring on British Airways flights, ranging from headache to myocardial infarct. Most of these were dealt with by cabin staff without calling for help from a doctor or nurse on board. In 559 cases help was given by a doctor or nurse responding to such a call; …