Quiz: A. incident B. when C. include D. flights E. informed F. carriages G. called H. serious I. stressful J. disaster K. command L .reluctantly M. confronted N. require O. easily As a physician who travels quite a lot, I spend a lot of time on planes listening for that dreaded "Is there a doctor on board?" announcement. I've been (1)____ only once-for a woman who had merely fainted. But the (2)____ made me quite curious about how often this kind of thing happens. I wondered what I would do if (3)____ with a real midair medical emergency-without access to a hospital staff and the usual emergency equipment. So (4)____ the New England j ournal of Medicine last week published a study about in-light medical events, I read it with interest. The study estimated that there are an average of 30 in-flight medical emergencies on U.S. fights every day. Most of them are not (5)_____; fainting and dizziness are the most frequent complaints. But 13% of them-roughly four a day-are serious enough to (6)_____ a pilot to change course. The most common of the serious emergencies (7)____ heart trouble, strokes, and difficulty breathing. Let's face it: plane rides are (8)_____ . For starters, cabin pressures at high altitudes are set at roughly what they would be if you lived at 5,000 to 8,000 feet above sea level. Most people can tolerate these pressures pretty (9)____, but passengers with heart disease may experience chest pains as result of the reduced amount of oxygen flowing through their blood. Another common in flight problem is deep venous thrombosis-the so-called economy class syndrome. Whatever happens, don't panic. Things are getting better on the in-flight-emergency front. Thanks to more recent legislation, (10)_____ with at least one attendant are starting to install emergency medical kits to treat heart attacks.