What’s the Most Refreshing Drink That’s Not Water?

For about 30 summers, Mindy Haar worked as the head lifeguard at a sleepaway camp in the Catskill Mountains. The teenage lifeguards under her charge wouldn’t always remember to drink water, so she remembers constantly nudging them to guzzle more H2O. The reminders worked. “I don’t recall any of my staff becoming dehydrated,” says Haar, who is now chair of the department of interdisciplinary health sciences at New York Institute of Technology.

Even if...