DEAR DR. GOTT:
Recently, at a movie, the person behind me coughed on me through the entire film. The next morning I awoke with the beginning of a cold. My head and chest were congested.

My wife says it would have been impolite to move. She also insisted that I could not have caught a cold that quickly. I think otherwise since this has happened on several previous occasions. I am curious to know if a cold can really take hold within 12 hours after initial exposure.

DEAR READER:
Let me start by saying it would not have been rude to change seats in the theatre. It is, however, more than rude to cough on someone throughout an entire movie. The person should have been considerate enough to sit in an isolated area to reduce the spread of the cold virus. Better still, this person should have stayed home to avoid potentially contaminating every person with whom he or she came in contact. Colds are not harmful but can be very unpleasant. In my opinion, those infected should avoid all unnecessary contact with others until symptoms have subsided; this includes going to the movies.

Now to your question. My answer is, yes, it is possible to start developing symptoms within 12 hours after exposure. However, it is not normally that quick. For most healthy individuals, a cold needs to incubate for 24-48 hours before the start of symptoms. Peak symptoms appear after 36-72 hours. If you have repeatedly experienced rapid onset of cold symptoms you may have a mildly weakened immune system. This could be caused several things such as improper diet, certain medications or smoking. If you are otherwise healthy with no anemia, fatigue, or other illnesses, I wouldn’t be worried.
One option you may wish to try is simply adding more fresh fruits and veggies to your diet as well as increasing exercise. This should boost your immunity and stave off future infections.

Another option is to take a multivitamin daily. This may improve your health by supplementing your diet with extra vitamins and minerals that you may be lacking.

Finally, if you have any unexplained symptoms such as repeated infections anywhere on or in your body, fatigue, anemia, or easy bruising, I recommend you visit your primary care physician for further testing to rule out a serious cause.