AP Photo

I moved to New Delhi a year and a half ago from New York for a new job with a newspaper. When I arrived in India's capital, I figured if I was going to live in the country, I might as well get used to the food, the water and the bacteria that doesn't seem to bother too many natives. I ordered juices, ate cold salads and drank the un-bottled water that restaurants bring customers for free. But I learned the hard way there are better methods for adjusting your body to the new climate. Less than two weeks into my time there, I found myself vomiting at the foot of a 12th century monument, the Qutb Minar.

I had anticipated getting sick in India. Since I had elevated carelessness to the level of doctrine, I had almost guaranteed it. But it was something I hadn't prepared for. I had no...