From what I know in the hi tech world, it's not so much that they pay you more -- though some hardship pay seems appropriate -- as that things should be set up in such a way that in addition to salary, you basically get all your living expenses paid.
That is, you should get a per-diem for every day you travel that covers housing, food, travel, and communications. Your only expense back home then is paying the rent. AND none of the money you get paid for travel should be taxable.
In other words, it's not so much that you get a higher salary as that you get a salary you don't actually have to spend much of.
Joanna