The Biggest Hygiene Mistakes People Make in the Pool

On a 95°F day, when you’re drenched with sweat and desperate to cool down, a swimming pool might look like the most beautiful thing you’ve ever seen. But to the people who study pool water for a living, it’s more like a warm, lightly chlorinated broth of everything a few dozen bodies carried in with them. That's not a reason to stay on dry land—but it is a reason to know the handful of habits that can tip a day at the pool from refreshing to regrettable.We asked infectious disease doctors and water-quality experts which hygiene mistakes they see most. Here's what you're probably getting wrong—and what to do instead.You think chlorine zaps everything the second it hits the waterChlorine is a genuinely great disinfectant, but it doesn't work instantly, and it's not all-powerful.Ordinary bact