Just as a major heatwave is beginning to descend on the midwest, the Centers for Disease Control have issued a warning about pools. They say a parasite that can cause victims to be sick for weeks continues to worsen.

The fecal parasite is known as Crypto, which is short for Cryptosporidium. Though only one person has died from it in the last 10 years, the number of people stricken with Crypto went up an average of nearly 13 percent every year from 2009 through 2017. Most cases come in July and August when the parasite can be ingested when a swimmer swallows water that is contaminated. Infected cattle can also infect humans as can child care settings where contact with infected people can occur. Healthy adults can be stricken with "profuse, watery diarrhea" for up to three weeks. Kids, women who are pregnant, and people with immune systems that are comprised can be impacted even worse.

How do you prevent it? The CDC report says don't swim or attend child care if ill with diarrhea and they also recommend hand washing after contact with animals.