This summer, swimming pools will be filled with millions of people having fun and staying cool. But did you know that germs can contaminate swimming water even if it is treated with chlorine? Learning about recreational water illnesses (RWIs), which are spread by swimming in contaminated recreational waters such as swimming pools, waterparks, lakes, and the ocean, can protect you from illness.

RWIs are caused by germs like “Crypto” (KRIP-toe, short for Cryptosporidium), Giardia (gee-ARE-dee-uh), E. coli 0157:H7, and Shigella (Shi-GE-luh) and are spread by accidentally swallowing water that has been contaminated with fecal matter. How does a pool get contaminated? You share the water with everyone in the pool. If someone with diarrhea contaminates the water, swallowing the water can make you sick.

The great news is that germs causing RWIs are killed by chlorine. However, chlorine doesn’t work right away. It takes time to kill germs and some germs like “Crypto” are resistant to chlorine and can live in pools for days. That is why even the best maintained pools can spread illness. Therefore, Healthy Swimming behaviors are needed to protect you and your kids from RWIs and will help stop germs from getting in the pool in the first place. Here are six “PLEAs” that promote Healthy Swimming:

1. PLEASE don’t swim when you have diarrhea. This is especially important for kids in diapers. You can spread germs in the water and make other people sick.
2. PLEASE don’t swallow the pool water. In fact, avoid getting water your mouth.
3. PLEASE practice good hygiene. Take a shower before swimming and wash your hands after using the toilet or changing diapers. Germs on your body end up in the water.
4. PLEASE take your kids on bathroom breaks or change diapers often. Waiting to hear “I have to go” may mean that it’s too late.
5. PLEASE change diapers in a bathroom and not at poolside. Germs can spread to surfaces and objects in and around the pool and spread illness.
6. PLEASE wash your child thoroughly (especially the rear end) with soap and water before swimming. Everyone has invisible amounts of fecal matter on their bottoms that ends up in the pool.

Want to learn more about recreational water illnesses (RWIs)? Why you shouldn’t swim when ill with diarrhea? How some germs that cause RWIs can live for days in even the best-maintained pools? Go to www.cdc.gov/healthyswimming for more information. Take the Healthy Swimming IQ Quiz and a quick look at what swimmers are asking this year.