Perhaps the only thing that can make an oppressively hot day worse, is knowing that the refreshing pool you’re about to dive headlong into might be a cauldron of fecal disease.

Then again, it might not be so long as people follow health guidelines.

With the summer season underway, the Salt Lake County Health Department is again urging swimmers to protect themselves and others splashing in the water by, well, washing your ass before you submerge it.

In 2007, Salt Lake County had a rash of more than 2,000 Cryptosporidium (crypto) cases, says Salt Lake County Communications Coordinator Nicholas Rupp, and in response, local officials launched an aggressive media campaign to curb contractions. It seems to have worked. Crypto outbreaks declined since, according to Rupp, but the county still aims to send out a hygiene reminder each year to keep those numbers low.

In addition to thoroughly washing yourself, the county is reminding swimmers to refrain from swallowing water, stay out of the pool for two weeks after experiencing diarrhea, don’t change diapers by the water, wash your hands and take children out for regular bathroom breaks “because if you wait for them to say something, it’s probably too late,” Rupp warns.

These recommendations are taken from the Centers for Disease Control, which recently released the squeamish results from a national survey. The CDC found that 25 percent of adults would swim within an hour after experiencing diarrhea; nearly half admitted that they don’t shower before swimming; and 60 percent said they swallow pool water.

“And 1 in 5 admit that they pee in the pool,” Salt Lake County Water Quality Supervisor Rick Ledbetter says in a statement. “That doesn’t include adults who don’t admit it, or children who may not know better.”

Causing irritable diarrhea, crypto is particularly vicious because it can survive chlorinated pools or hot tubs for up to 10 days, Rupp says. All county-run pools use UV filtration, which does kill the bug.

“The problem with UV filtration is it can only filter so much water per hour,” he continues. “When you have a really big body of water, it can take a long time for all the water to filter through.”

Since the filter system can only offer so much protection, officials are asking the public to do their part.

“It’s best to keep poop out of the pool in the first place, so wash often and wash well,” Ledbetter continues in his statement. “And in case others aren’t as responsible as you—keep the pool water out of your mouth.”