This began as a private message, but it may be useful to anyone planning a summer trip in Central Europe. Don't get me wrong, we thoroughly enjoyed our trip, but my advice is, don't be hardheaded about cooling off.
To wrap up a longer trip, we just spent the first 10 days of June in southern Bavaria, staying in family-run places in Oberammergau and outside Berchtesgaden. The weather was very warm for early June, and our rooms became too hot to endure between 10 a.m. and 8 p.m. That's not a problem if you manage to spend every daytime moment away from your lodgings. Things did cool off at night, but this was still officially late spring, not summer. By July, when the heat is more intense and sunset is around 9 p.m., the rooms will not cool off until the early morning hours, then reheat by mid-morning.
This was our second trip to the Bavarian Alps in two years. We visited the area in late July and early August 2013, when most of Europe was experiencing a heat wave as bad as any we have had in Alabama, which is in the hottest, most humid part of the American South. But we have AC in our homes, cars, restaurants and businesses here. Friends who had been to Salzburg a couple of summers earlier warned me to get an air-conditioned hotel. And I did. But I canceled it for a place in the mountains, where it is "always cool." That was the biggest travel mistake of my life because it endangered others. Even atop Mt. Jenner, temps were in the 90s F. My wife suffered a mild (her term, not mine) case of heat sickness, but she had no cool place in which to recover other than our rental car. She came through it ok but I should have listened to the advice about AC.