Randy Cohen writes "The Ethicist" column in The New York Times Magazine. If you'd like help with a moral dilemma you're facing at school, at home, or at work, send your question to: ethicist@nytimes.com or The Ethicist, The New York Times Magazine, 620 Eighth Avenue, 6th Floor, New York, NY 10018, and include a phone number.

When my flight to China landed, health officials in full protective gear took everyone's temperature with noncontact sensors. Before landing, we were given questionnaires asking if we had a fever or cough, and if we had noticed anyone with flu symptoms to provide their seat numbers. Was I obliged to inform on other passengers?
LARRY LOCKER, POMPANO BEACH, FLORIDA

IT'S ALL in how you phrase the question. If asked whether you should "inform" on other people, the instinctive answer is no. But when asked if you have a duty to give honest answers to health officials working to deter a pandemic like swine flu, the answer is yes, you do.

Those officials were not trying to stifle anyone's free expression or political thought. They were performing a legitimate function, worthy of cooperation.

Passengers eager to enter China might lie to health officials, and so the latter were wise to seek information from multiple sources.

You might phrase the question yet another way: Should you cover up a potential disease carrier and abet the spread of flu?

UPDATE: Locker responded only generally to the health officials, that there were people seated near him who coughed frequently, but he did not give their seat numbers, as requested on the form. "I didn't finger them," he said.

Two friends bicycling in Connecticut ran into a summer thunderstorm. They first stopped beneath a tree, then rode to a private house and knocked on the door. No one answered. The car parked in the driveway was unlocked, so they took shelter in it. I think this was wrong. They disagree. You? DMITRI WOLKOFF, BROOKLYN , NEW YORK

I'M WITH YOU. Such liberties might be taken during a genuine emergency—had it been raining frogs, for example—but not if it was merely raining rain. The dangers of getting wet do not justify commandeering someone else's car.

Nor was car-squatting their only option. Your friends were in Connecticut, not up the Amazon. Had they ridden a bit farther, surely they could have found shelter. Another flaw in their survival strategy: They stood under a tree in a thunderstorm. Have they never been Scouts?

(The New York Times Upfront, Vol. 142, November 23, 2009)