Extreme heat is dominating our lives right now. It’s uncomfortable, it’s expensive, it’s deadly, and it’s proving to be a disaster for people and the environment.

So far this summer, temperatures have broken records nationwide, routinely reaching into the triple digits as a heat dome and other extreme temperatures marked the beginning of summer and the school holidays.

While some families might have a pool, a cold plunge, or are lucky enough to have insulated water pipes, the rest of us must make do with the beach or the many watering holes dotted throughout the nation’s vast river network.

The only problem is many of these outdoor spaces are covered in sewage from municipal overflow and are teeming with various types of bacteria, which can pose greater health risks for the millions of people who turn up in these places during heat waves, according to recent reports and environmental advocates.

And the issue is getting worse.

In 2022, 55% of American beaches were found to be covered in fecal bacteria for at least one day, up 2% from the year before, according to a study, while approximately half of lakes and rivers nationwide are too polluted for swimming, fishing, and drinking.

What does that mean for people?

“Higher levels of fecal indicator bacteria are correlated with more cases of illness,” said John Rumpler, co-author of the beach study and the Clean Water Director at Environment America, a Colorado-based advocacy coalition made up of environmental groups in 30 states. “Also, hotter [temperatures] exacerbate a different water pollution threat – toxic algal outbreaks.”

If you don’t know what fecal bacteria is, it’s generally considered to be poop from humans and animals.

The algal outbreaks, on the other hand, are a type of bacteria that often grow out of fertilizer runoff from farms, pollution from industrial sites, and sewage. It looks like foam or scum that covers the surface of fresh or saltwater, according to the Centers for Disease Control. They also come in various colors, are toxic to people and animals, and typically grow in hot temperatures.

And hot weather is something we have plenty of right now.

Around 50 million people are still under an extreme heat warning, a figure that’s expected to spike again in the coming days, with over 100 million people in the Midwest and Northeast anticipating temperatures firmly in the 90s but approaching the 100-degree mark, which is between 5 and 15 degrees above historical averages for those regions, according to forecasts.

Water temperatures have also been extremely high recently. In South Florida’s shallow coastal waters, temperatures exceeded 100 degrees last week, which experts have claimed could be a record for seawater temperature. Marine experts say that entire stretches of coral reef have died and expect that to continue if high temperatures sustain.

What’s the worst that can happen if you decide to take a dip in bacteria-laden water?

It can lead to ailments such as digestive disorders, respiratory illnesses, infections in the ears and eyes, as well as skin rashes, according to the nationwide beach report. It’s estimated that in the U.S., every year, there are approximately 57 million instances of illnesses caused by swimming in various bodies of water like oceans, lakes, rivers, and ponds. A significant number of these cases, however, remain unreported, according to the report.

But it’s not all bad.

“On most beaches, there are still many days when the water is safe for swimming,” said Rumpler. “So I think it is unlikely that people will stop going to the beach. Nor should they.”

And it turns out people continue to head to the beach in huge numbers. While there isn’t a ton of data on who goes to the beaches and watering holes, it’s estimated that around 180 million Americans made 2 billion trips to the beach in 2017. In 2021 alone, Panama City Beach in Florida welcomed 18 million visitors, a 50% increase from pre-pandemic levels. Rumpler added that while high heat levels alone may not make fecal bacteria worse, its presence during hot periods does increase the danger posed to humans.

“Heat does add to the urgency of making our beaches safe for swimming, as more people need ways to cool off,” he said. But not everyone does go.

A 2017 UCLA study noted 77% of Californians visited the coast at least once a year, with most being under 40, parents of children under 18, and those residing in coastal communities. You’re less likely to see people visit from the Central Valley region or those who are over 65, or African Americans. Over 60% of those polled said that beach access was a major barrier to going, while over 75% said that it was not affordable to park and find accommodation.

For those who don’t live near beaches, similar issues exist at so-called watering holes, like lakes, ponds, and areas where people swim in rivers.

Sewage overflows, usually from nearby towns and cities, also pour into the nation’s bays and rivers. In hot weather, the level and flow of water in these areas often decrease, causing stagnant pools. This is a breeding ground for various types of bacteria. But it can also cause more significant issues that aren’t great for human health.

“As temperatures rise, you can have oxygen depletion that puts stress on fish very fast,” said Tonya Bonitatibus, the executive director of the Savannah Riverkeeper, an organization that protects and monitors a 10,500 square mile watershed that supplies drinking water to 1.4 million people. “The fish die, and the bacteria explode even more.”

She added: “And that’s not a place people need to be.”

When fish die like this, it’s known as “fish kills,” and it nearly always occurs because of heat and low oxygen.

And the same thing applies to coastal waters, where flesh-eating bacteria like vibrio can linger.

“The bigger public health issue with fish kills and humans being in the water is the bacteria will start growing around the decomposing fish, which could also pose a human health risk,” said Samantha Barquin, chief of staff at the Miami Waterkeeper.

In August 2020, for example, Biscayne Bay, right next to the enormous Miami metropolitan area, saw 27,000 fish die from a lack of oxygen, no tidal flow, extreme heat, and too much pollution.

Why are so many of our beaches gross?

“One of the primary threats is aging sewage infrastructure, which is struggling to keep up with the demands of a growing population,” added Barquin. “But many other places experience this, too.”

Barquin, who has also worked as an environmental technician and science and policy project manager at the Miami-based environmental advocacy group, said that sewage ends on beaches after overflows release untreated or partially treated sewage into waterways.

It can be worse after heavy rain.

This all comes after Florida’s beaches saw vast amounts of seaweed wash ashore in late spring. The sargassum, as it’s known, contains bacteria harmful to both humans and animals.

Needless to say, Gulf Coast beaches were some of the dirtiest in the country, with researchers noting that 84% had at least one day of fecal contamination. In Texas, where temperatures have been as high as 125 degrees, 90% of beaches came back with unsafe contamination levels. California’s beaches were at 75%, Florida was at 70%, and Louisiana was at 100%.

What are the solutions?

Unfortunately, solutions aren’t cheap and divisions around environmental protection are often dominated by political ideology.

“The key solution to make our waterways safer for swimming is to invest in better water infrastructure to prevent sewage overflows and runoff pollution,” said Rumpler. “Unfortunately, Republicans in Congress have just proposed deep cuts to the Clean Water State Revolving Fund, the main federal program for funding wastewater infrastructure.”

The proposed cuts from the GOP-run House of Representatives would reduce state programs that monitor drinking water and clean water, in addition to a 42% cut in the State and Tribal Assistance Grant, an environmental grant that helps with air and water quality. Overall, the budget would cut the Environmental Protection Agency’s funding by 39%.

While that U.S. House budget will have to be reconciled with a Democrat-run Senate budget, It seems unlikely that new sewage infrastructure is coming to your municipality anytime soon.

So, how do you stay safe in contaminated water?

The best way to avoid becoming ill from contact with water is to ensure you know the bacteria levels. Most states, counties, and cities monitor water that people are in contact with regularly. Some people will be put off by anything other than pristine water, while some might risk it to get out of the extreme heat.

Everyone is probably aware of the basics, like don’t swallow the water and make sure your place band-aids over any cuts and abrasions. But there are other things you can do to lower the chances of getting sick.

“We always tell people to wait 24 to 48 hours after a big rainstorm before getting in the water,” said Bonitatibus, who advises downloading the Swim App, which uses government data to monitor beaches and swimming conditions worldwide. “That’s when most of the bacteria runoff gets in the water.”

Make sure you shower before and after being in the water. Showering after seems obvious, but showering before ensures you’re not contaminating the water with bacteria on your body. And without going into the gory details, you do have gross bacteria on your body.

It’s also important to take children on regular bathroom breaks, especially the ones who still wear diapers.

Lastly, check the weather. Warm weather and even light rainfall can increase the bacteria levels in lakes, rivers, and streams. Precipitation can help sewage runoff into swimming holes, while even just a light rain can stir up bacteria within soils that can then flow into bodies of water.