Swimming in a pool or soaking in a communal hot tub are super fun things to do in the summer, but can also become injured, or something in the water can make you sick. You can scrupulously chlorinate and maintain your own pool, and trust your friends and family to do the same, but when venturing in public swimming pools, you can perform some quick checks as a health precaution.

The most common waterborne illness is diarrhea, which you may not even attribute to your family’s trip to a pool or water park. Cryptosporidium (commonly called Crypto), Giardia, Shigella, norovirus, and E. coli O157:H7. These illnesses spread when fecal bacteria ends up in the pool (we’re sure you can figure out how that happens), and the levels of disinfectants aren’t high enough to kill the virus or bacteria.

Other unexpected infections spread at the pool include skin, eye, and ear infections caused by bacteria in the water. Pseudomonas Dermatitis or Folliculitis is a contagious infection of the skin or hair follicles that you can contract after spending a long time in water that hasn’t been properly disinfected.

It’s often associated with hot tubs, but can also happen in pools or even lakes. One way to avoid it is to not sit around in your swimsuit for a long time after soaking in a hot tub, to shower after getting out, and to make sure to launder your suit between dips.

Legionella, the bacteria that cause Legionnaire’s Disease, can also grow in water that isn’t properly disinfected, and can cause fatal pneumonia, especially in people who are elderly, former smokers, or immunocompromised.

This isn’t meant to scare you out of going to pools, hot tubs, or water parks, of course. What you need to keep in mind are the CDC’s tips for keeping yourself and your family from getting sick or injured in the water, and maybe stopping outbreaks in their tracks.

Carry your own test strips and check the water before getting in. Disposable strips are inexpensive and easy to find, and you can easily throw them in a bag with your towel. Sure, you might look paranoid, but I’d rather look paranoid than have norovirus again.

Can you see the drain at the bottom of the pool? This is to make sure that the water isn’t cloudy, and that lifeguards and other people around the pool can see to the bottom in case there are swimmers in distress. Speaking of which…

Make sure that the drains are securely closed. People can get hair, swimsuits, or parts of their body trapped in a drain and drown.

Is there a lifeguard, or rescue equipment? If you don’t see equipment like flotation devices or a pole, maybe don’t bother swimming that day.

Thousands of public pools, hot tubs closed due to serious violations [CDC]

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