India, Oct. 3 -- You have booked the flights, sorted the hotel and maybe even planned a few restaurant stops. But one question tends to get left for the last minute: how much medical cover do you actually need?

Pick too little and a hospital stay abroad could eat into your savings. Pick too much and you pay for protection you may never use. The answer is not the same for every traveller. A lot of it depends on where you are headed.

Why Does the Destination Matter So Much? Healthcare costs vary wildly from one country to another. A doctor's visit in Thailand is a very different bill from the same visit in the United States. Even a simple emergency room trip in some countries can run into thousands of dollars before treatment begins.

The...