Kattie, I just returned from 3 nights in 90 degree weather in Vienna, and after the first night at a pension without AC, we changed to Courtyard Vienna Schoenbrunn, which I really recommend. It's a little south of main Vienna, but 200 meters from a subway stop that will whisk you anywhere in 15 minutes. The room was spacious, the only place we stayed in Europe with separate double beds. The bathroom was large and really clean. They offer a breakfast (too expensive for us), have a restaurant for dinner (a little pricey, but we ate there once), and have a small shop in the lobby as there isn't much to eat/buy around the hotel. But you are within walking distance of the Schonbrunn Palace, which had a restaurant and lots of food carts outside it. We got a good deal at Expedia (just a little over $100 a night). Look into it! I am so glad we ended up switching to this hotel.