In addition, the CDC’s interim guidance for flight crews indicates that they should provide masks for passengers showing symptoms of flu, and try to separate them from other people on the flight as much as safety will allow. But it might be worth packing a respirator mask, which can provide some protection against infection, in case you are around travelers with symptoms, or to protect others if you develop symptoms yourself. But make sure you get one that has been cleared by FDA, or bears a label from the National Institute for Occupational Safety and Health (NIOSH) as rated N-95* or higher.

Alcohol based hand sanitizers containing at least 60 percent alcohol, like Purell, can also help in a pinch, when you don’t have access to soap and hot water to wash your hands. Finally, you may want to wipe down the arm rests and tray table in your area with an alcohol wipe.

—Kevin McCarthy, associate editor

* Update for November 2, 2009: A 2009 study finding that N-95 respirators were superior to surgical masks at preventing the spread of flu was retracted by the authors after a flaw in the methods was discovered. The authors now say there is no significance difference between N-95 respirators and surgical masks, confirming another recent study that found they were equal.