If you’re about to take your kids to a waterpark like Bissell’s Hideaway, be sure they—and you—wear nose plugs even if you’re just going on milder water slides. Waterparks and water slides aren’t usually seen as very rough, except for the more advanced slides, and many people think they can forget protective gear like nose plugs. However, water at even the best parks can present a problem for slide users as they hit the pool at the bottom of a slide. Wearing nose plugs prevents a lot of discomfort both as you plummet off a slide’s exit flume and long after you leave the park.

Water up the Nose

Very gentle water slides often have exit flumes that lead directly into the water, but slightly more advanced ones usually lift the edge of the flume above the water. So, instead of sliding right into the pool, you fly off the edge and end up making a sloppy cannonball-type landing in the water.

The force with which you hit the water is similar to what you’d get by jumping or diving into a pool, which means there’s a good chance of water shooting up your nose and into your sinuses. At best, this is highly annoying, but it can also be physically irritating if there’s a lot of chlorine. To help keep the water out, wear nose plugs as you go down each slide, even the mild ones.

Buoyancy Help

Some people try to mitigate the water-up-the-nose factor by exhaling through the nose underwater, but that reduces the air you have stored up. You run out of breath faster, obviously, but you also lose buoyancy. The more air you have in you, the easier it is to get back to the surface of the water. If you have nose plugs preventing water from getting up your nose, you won’t have to worry about compensating for the loss of buoyancy with stronger swim strokes.

Brain Safety

A clean, properly disinfected, and well-maintained water park that has artificial pools should not pose a problem in this regard, but if you go to parks that base their pools on natural lake formations—especially if the bottoms of the pools are made of sand—then you must wear nose plugs. The reason is a growing risk from the Naegleria fowleri amoeba, a warm-water resident present in lakes and rivers in the United States, mainly in the southeast but also in water in the Upper Midwest and Great Lakes region.

The amoeba is harmless if you ingest it, say through water splashing into your mouth. But if it gets into your nose and can make it into your sinuses—and then your brain—the infection, known as primary amebic meningoencephalitis (PAM), can be fatal. Infections are rare, and deaths even rarer; CBS News says only 128 known cases have occurred in 40 years, from 1962 to 2012. And these cases include infections from many sources, not just water slides. However, the risk is real, and wearing nose plugs helps you avoid infection.