Okay, it's not rocket science, but unless you're one of those people that like to pack voltage converters, read up. I'm not sure how high voltage converter ranks on things to pack, but I bet it is more likely to be left behind than the hair dryer.
The best way to prevent frying a hair dryer (or a travel adapter) is to simply keep the hair dryer on low heat when it is on. Test those waters and fate, if you want, by cranking that setting up to high but don't say we didn't tell you so.
(Five dead hair dryers and endless fried travel adapters were sacrificed in the making of this article.)
The other foolproof method is packing a voltage converter.