Londoners might not feel the full heat of the summer at the present time, but we already had our own little heat wave earlier this season. Posters all over the tube stations and in public transit systems all over the world caution you to stay hydrated, and for good reason. Doctors recommend we consume eight 250ml servings of liquid every day during the summer.

During this high tourist season, its easy to reach for bottled water at your local Tesco Express rather than buying an aluminum refillable bottle. This decision puts a non-biodegradable bottle into the environment for centuries; that's a costly long-term commitment to environmental damage for a few ml of water. Fortunately, aluminum bottles are becoming very eco-chic and are available almost everywhere. Even if you don't own one, pick one up at your next tourist destination. Not only will you get a cool souvenir, you'll be helping out the environment too. This is especially important if you are visiting the United States, Europe, Australia, and other highly developed countries, because you'll be able to fill your new aluminum bottle with clean, well-regulated tap water. If you are traveling elsewhere, ask your lodgings where to find environmentally sustainable, clean water. Unfortunately, some countries do not have access to clean tap water; in that case, make sure you recycle your plastic bottles rather than throwing them away. No matter where you visit, simple decisions regarding your intake of water can have huge environmental impacts, so think carefully before you purchase that Evian!