Some of the most common types of recreational water illnesses (RWIs) include: • Swimmer's ear (otitis externa) - This is an infection in the outer ear canal that can result in pain, itching, swelling, and other frustrating symptoms. Swimmer’s ear often occurs when water becomes trapped in the ear, creating an optimal environment for bacteria to grow. • Cryptosporidium - This waterborne illness leads to watery diarrhea, stomach cramps, nausea, and vomiting. Infection frequently happens when contaminated water is ingested; Cryptosporidium is very resistant to chlorine and can survive in pools for up to ten days. • Giardia - This parasitic infection leads to diarrhea, gas, stomach pain, nausea, and dehydration. Like Cryptosporidium, Giardia can be spread through swallowing contaminated water and can take a while to be killed by chlorine. • Norovirus - As it is highly contagious, norovirus can spread quickly through contaminated water in pools, lakes, and oceans. This virus causes a sudden onset of vomiting and diarrhea. To minimize the risk of these illnesses and other RWIs, such as E. coli and Shigella, you should avoid swallowing water while swimming, shower before and after swimming, and ensure pools and hot tubs are properly maintained.