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Whatever you do, do not use alcohol to try to make your spot in coach more palatable. Alcohol can have unwanted side effects at altitude, and imbibing puts unnecessary stress on your system. The good news is it can be much harder to lay off the booze in business class, where flight attendants keep it flowing freely throughout the flight. Opt for club soda or just water, and you'll save yourself a nasty hangover and a lingering case of jet lag in the end.