About a year ago, I went on holidays to Hungary for a week. I used my 770 on the train to watch a movie and for reading eBooks. After having arrived in Hungary, I didn't use my 770 the whole time. On my last day in Hungary, the device even got wet in my backpack due to walking through Budapest while it was snowing like hell.
On the train back to Germany, I noticed that the device became wet (luckily it survived) and was still running!