It's important to remember that chlorine doesn't kill all germs instantly. So no matter if it's a swimming pool, hot tub, or water park there's always a chance you're swimming in contaminated water.
Dr. Susan Rehm, who treats infectious diseases at Cleveland Clinic, stresses that there is one thing you should never do when swimming.
"The most important thing is to avoid swallowing water," said Rehm. Note that swallowing even a little contaminated water can make you sick.
It's also helpful to pay attention to bacteria levels in lakes, rivers, and streams. This is especially important on really hot days and after heavy rainfall, which causes bacteria counts to rise.
Researchers with the Centers for Disease Control and Prevention say diarrhea is the most common recreational water illness. But the list also includes: skin, ear, and wound infections.
To prevent illness Rehm advises shower before and after swimming.
"Shower and clean off afterwards. Again, careful attention to hand-washing, as well," said Rehm. "Any bacteria that are on your hands can be transmitted to food, or you could touch your eyes or mouth with them and get infected in that way as well."
Lastly, Rehm reminds us to never swim if we're sick, or have an open wound, because there's a chance we'll contaminate the water for others.