Air conditioning is especially rare in northern European places like Britain or Denmark, and even in parts of France that historically have had colder winters and more temperate summers. That can become a problem for travelers in the summer, when climate change takes a toll on old hotels or rentals originally designed to retain heat.

While more of Europe now is turning to air conditioning, travelers who want AC should check with their hotel or Airbnb hosts directly to confirm it’s available.

“When we do trips for clients, that’s one of our questions: Do you need to have air conditioning?” said Ryan Villa, owner and operations manager of All Travel Guru, a U.S.-based agency specializing in European travel.

Even when AC is available, it may not be as potent as your unit back home, according to Ethan Jones, a travel adviser at Vincent Vacations. Air conditioners in Europe are often add-ons rather than centralized units, so they’re less efficient.

“Europeans are used to it being warmer, so they get the bare minimum AC to knock it down just 5 or 10 degrees,” Jones said.

In most European countries, bottled water is the default option at a restaurant. That means you’ll be paying for your water — sometimes more than for beer or wine — and there are no unlimited refills. You should also always clarify whether you want sparkling or still, just in case.

If you want tap water, you can ask, but it’s no guarantee the restaurant or bar will oblige. Asking for a “cup of water” in certain countries, like Spain, where restaurants and bars are required by law to provide free tap water when requested, will often get you tap water.

Regardless of the kind of water you get, though, it’s unlikely there will be ice.

Across Europe, and especially in southern European countries like Spain and Italy, there are plenty of beautiful public fountains where you can fill up a reusable bottle free.

Rome alone has approximately 2,500 water fountains spouting a constant flow of clean water. These water fountains often serve a double function: they’re decorative touches to the city’s ancient streets and can be a lifesaver in extreme heat. You can find a fountain just by walking around — or with tools like the Waidy app.

If you’re not sure whether a fountain has drinkable water, you can look up the specific rules for the place you’re in. In many countries, you can rest assured that a public fountain’s water is safe to drink unless you see a sign telling you otherwise.

While looking for a hotel for your trip, know that American standards for a certain class of hotel will not always line up with European ones.

“A three-star [in the United States] is a pretty clean, well-priced hotel. Over there, it’s going to be an older, lesser-staffed hotel,” Villa said.

If you’re looking to save money, there can be good options in the three-star range, but booking one might just require more research.

While U.S. hotels are more likely to offer larger rooms with king-size beds, Villa said the maximum size in Europe will often be a full or queen-size. You can expect smaller rooms and bathrooms, too.

“The newer hotels that they’re building, they’ve kind of caught on to what the American standard is,” Villa said. “But if you stay at an older, boutique hotel, you’re probably going to find a room that’s smaller.”

Bathrooms at boutique or budget hotels could resemble “RV-style” bathrooms because of their small size, Jones said. Because many buildings in Europe are older, space for bathrooms wasn’t always allotted, so they had to be added after the fact.

Travel expert Samantha Brown added that, sometimes, hotels will only provide one small towel. She thinks there’s a case to be made for bringing a small sports towel on your travels, just in case.

Because everything is generally smaller — and older (read: no elevators) — she also recommended travelers contact the hotel ahead of time if they have accessibility concerns.

Public restrooms in Europe can be found frequently in parks, gardens, train stations and even on the street. But there’s a catch: Unless they’re owned by a private business (and sometimes even then), those restrooms require patrons to pay a small price — not usually more than a euro — via a machine or to an attendant to use them.

Don’t expect every bathroom to look like an American one, either. Countries in Southern and Eastern Europe, for example, sometimes have squat toilets that sit in the ground. Many countries also forgo dividers between urinals.

U.S. tipping culture has permeated everything from dining at fancy, well-serviced restaurants to buying a coffee from a screen. In Europe, though customs vary from country to country, you aren’t expected to tip as often. And when you do choose to leave a tip, the standard is 10 percent, rather than 20.

Brown, who hosts several TV shows for the Travel Channel, said that while it can feel rude not to tip, it’s not as necessary an income source for service workers in Europe as it is in the United States: “They’re paid a living wage, they have health insurance,” she said. “They have all the bells and whistles that we don’t.”

“It also depends on what kind of facility you’re at,” Villa said, explaining that it still might be customary at a five-star hotel to tip a porter for carrying bags to your room.

Some restaurants now include an option to tip after paying on a credit card, but it’s not typically expected. According to Jones, you should use that option to show appreciation for exceptional service.

Europe has differently shaped and more powerful electrical outlets than the United States does, running at 240 volts rather than 120. To plug in your phone and other devices in Europe, you’ll need an adapter.

When picking out an adapter, it can be helpful to prioritize getting a smaller, more robust one to make sure you’re well equipped if you run out of juice while out on the town. A Type C plug adapter will serve you in all of Europe except the United Kingdom and Ireland, where you will need a Type G.

In many European countries but especially in the south, people eat much later than in the United States. Restaurants for dinner may not open until 6 p.m. or later, and probably won’t be buzzing with life until around 8 or 9 (unless the line is mostly tourists). For lunch, the standard mealtime is around 2 or 3 p.m.

“If they eat dinner late in Spain, eat dinner late in Spain, or know that you can go to a bar and have tapas anytime you like and call that dinner,” Steves said. “But if you insist at going to a restaurant at 7 o’clock in Madrid, you’re going to be eating with the staff.”

When you do go out to eat, portions will often be smaller than in the United States, and taking home leftovers may be frowned upon, depending on the country and setting.

In much of Europe, restaurants also charge a cover (“couvert” in France, “coperto” in Italy). This can either be a fixed rate per diner — kind of like a price for seating — or a fixed price for consuming the bread, olives and other small dishes that greet you at the table. The former must be paid, as it is a sort of service charge. If it’s the latter, you can avoid the charge by not eating the dishes or asking the waiter to take them back.

Be warned, though, that trying to get out of paying the cover can be seen as a faux pas.

While it’s not necessary (or possible) to attain fluency in a different language before every trip, it’s “always respectful to learn the basics,” Rose said.

Even learning a handful of words, like “hello,” “goodbye” and “thank you,” makes a big difference. “It goes a million miles. You would be surprised how much people appreciate it,” Brown said. “They don’t expect you to conjugate verbs, but you can be polite in another language.”

In some places, like France, it can even be seen as rude to walk into shops or restaurants without saying a quick “bonjour” or “bonsoir” at the door.

You should never walk into an interaction assuming someone speaks English, and asking if they do could be seen “as a challenge or put-down,” Brown said.

“That changes the dynamic immediately,” Brown added. “And when you’re in these places, you really are relying on the kindness of strangers.”

Though Europe can seem to many Americans as more culturally accessible or familiar than other parts of the world, every place follows its own etiquette and traditions.

“Get out of your comfort zone,” Steves said. “Think of culture shock as not something that you avoid … but the growing pains of a broadening perspective.”

Knowing from the jump that things will be different helps you avoid stereotypical tourist behavior.

“A lot of culture shock can happen because you’re not used to things being done in the same way,” Rose said. “That’s when entitlement comes through.”

Rather than being frustrated by smaller hotel rooms or the lack of iced coffee, she advised approaching everything with a “when in Rome” outlook.

“Put on your humility cap and don’t be afraid to be wrong,” Rose said.

While the above are general tips, Europe is a diverse continent. Each country has its own norms.

“Looking at Europe as a whole does it a disservice,” Jones said. “You can look at various regions — like the south, north, the Scandinavian countries and others — and each region has its own personality. Each country within the region will also have its own distinct personality, culture, food.”

In Spain, for instance, understand that “siesta” culture means many workers break around 3 or 4 p.m., and many businesses close for a few hours.

To make the best of any European vacation, Jones recommended travelers do some research so that they know what to expect. Just a little preparation, Jones said, “will make travels and interactions with people a whole lot easier.”