Blue-green water may not be so dreamy after all.
Swimming is a great way to cool down from the sweltering heat and squeeze in a cardio and strength training workout, but don't let the sight of bright blue water drown your better judgment. Not all swimming situations are created equal, and some can even land you or your loved ones in the emergency room if you're not careful. So before you slather on the sunscreen and grab your pool float, review this list of red flags. These signs are clear warnings that what might look like a day of summer fun could spell big trouble.