You know what you're not thinking about when you're traveling? The utility bills. When you're not paying the bill every month, it can be easy to overlook how much water or electricity you're using. Many places around the world don't have the same access to resources that you're used to, no matter how "developed" the country is. Many people in Spain, for example, turn off the shower between shampooing to keep the exorbitant cost of water down. If you're staying in locally-owned or family-owned accommodations, consider what resources you're using and if the price of your room really covers it. These are real people picking up the bills – not a blind organization. Do take your post-flight rinse, but maybe save the 45-minute hot showers for when you get back home.