I've been in Europe for most of the past month, and it is hot everywhere. Europeans love heat, and have no desire to allow any cold air into their buildings. Even when the temperature outside drops to say 55 degrees overnight, my unairconditioned rooms have been misery. Having the window open is not enough without air circulation.

I looked on Amazon and they make a 10-inch fan with a re-chargeable battery. I do not plan to go to Europe again without one to at least stick in the hotel window to try to bring in a little bit of cold air. In addition, I figure I can put it into my backpack/computer-bag and use it on the plane if it is too hot, which is about 80 percent of the time.