There's no better way to cool off on a hot day than with a swim. Swimming is a great way for kids to stay active and have fun during summer vacation, but it comes with some risks, too. Whether you're diving into a pool, a lake, or the ocean, waterborne illnesses are a concern. Fortunately, some common sense safety measures can help your family swim safely this summer.

What is a recreational water illness?
The Centers for Disease Control and Prevention (CDC) defines a recreational water illness (RWI) as one that is "spread by swallowing, breathing, or having contact with contaminated water from swimming pools, spas, lakes, rivers, or oceans."

There are several RWIs to watch out for. The most common waterborne illnesses include E. Coli, Cryptosporidium, Giardia, Shigella, and norovirus. All of these illnesses cause diarrhea. Less common RWIs include skin, eye, and ear infections, respiratory infections, and neurologic infections. These have numerous common symptoms including: coughing, rash, fever, and more.

How do RWIs spread?
In most cases, RWIs are spread from person to person. A person infected with a diarrheal illness may have an accident while swimming, which introduces the microbe to the common area. When another swimmer swallows that water, he or she may also pick up the infection. This is the case no matter the body of water: pools, lakes, oceans and rivers. Some other bacteria that cause RWIs live in the water. If a swimming pool or hot tub isn't properly sanitized, it can become a breeding ground for germs. And waters such as lakes and ponds may contain animal waste or industrial runoff or sewage.

Swallowing germs isn't the only way to catch an RWI. An open wound makes a swimmer more likely to get an infection, because it provides the germs a direct route to the bloodstream. Children are especially vulnerable to recreational water illnesses, but pregnant women, the elderly, and people with compromised immune systems should also exercise extra caution

How can you prevent RWIs?
Don't assume that water is sterile just because it's been chlorinated. It can take time - days, in some cases - for chlorine to kill some of the tougher germs. Everybody can pitch in to prevent the spread of recreational water illnesses. The CDC recommends the following six steps to prevent the spread of RWIs:

• 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.
• Don't swallow the pool water. In fact, avoid getting water your mouth.
• 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.
• Take your kids on bathroom breaks or change diapers often. Waiting to hear "I have to go" may mean that it's too late.
• Change diapers in a bathroom and not at poolside or on the beach. Germs can spread to surfaces and objects in and around the pool or on the ground and spread illness.
• 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 water

Besides practicing good hygiene, be aware of the conditions of your local swimming hole. If conditions are favorable for the spread of disease, there will often be a notice posted. At a public or private pool, talk to the staff to get an idea of their hygienic practices, and whether they have a history of outbreaks. Taking the time to ensure your family's health before diving in will help you enjoy aquatic fun all summer long.