Sitting in one of a line of seats at the United Airlines gate on Saturday evening, my wife and I were excited about the week’s vacation that lay ahead of us.

I had carefully avoided contact with anyone who exhibited even the slightest signs of illness last week, because I’ve had too many vacations where I spent most of my time sick in some hotel room to want to repeat the experience.

Arriving at our assigned gate, we settled into our seats for the hour-long wait for the plane that would take us out of Virginia.

Ever since 9-11, whenever I fly I find myself engaged in the new American pastime of “Spot the Potential Terrorist.” I’m not ashamed to admit that I’m somewhat careful when it comes to the safety of my family and myself. If I someday notice a worried fellow passenger wearing a ski jacket during the summer and furtively hiding his face whenever law-enforcement types pass by, there’s a good chance I’ll say something to someone in authority.

Happily, the gate area at Norfolk International Airport was free of such characters, and my wife and I settled in to read our books while we waited.

That’s when I noticed the businessman sitting across from us and about five seats down. He was pecking away on his laptop while issuing brusque commands via cell phone to someone in Washington or New York or wherever his important business had begun.

Nothing to worry about, except for his incessant phlegmy cough. I glanced at my wife, who seemed oblivious to the danger in our midst, and then I tried to go back to my murder mystery. But his cough seemed to punctuate every paragraph. Nudging my wife, I mouthed the words, “Swine flu?” She just rolled her eyes and went back to her book.

I wondered whether the terminal’s traveler’s store carried surgical masks, and then realized I’d probably be the one to look suspicious if I were wearing one. I began to consider that the air in the plane’s cabin would be recirculated for the entire flight and wondered how long it would take for the symptoms to show in one of us.

We didn’t see the man after we got our seats on the aircraft, and four days later, we’re still symptom-free, which is a very good thing. But I’ve thought about my worries several times since then, and about how things have changed in recent years.

Was it callous of me to think of my own safety in the face of this man’s suffering? I feel bad about it. And I recall a flight or two where my own snuffling and honking probably worried my fellow passengers. In those cases, I needed to get home and figured I’d just have to deal with being sick on the flight. I imagine the businessman on Saturday felt the same way.

Perhaps in this world of superbugs and pandemics, we need to rethink how we deal with sickness and travel. I, for one, am considering adding a surgical mask to my travel kit — not for protection against other people’s illnesses, but to protect them from my own when I must travel sick. It’s a brave new world we live in, and we must all do what we can to look after one another.