For most swimming enthusiasts, there is no better time than scorching summer days to take a plunge into cooling waters. Yet, most pools this time of year are always crowded, be they indoor or outdoor ones. To avoid throngs of others and, perhaps, to fully enjoy the fun that swimming brings, some people go to rivers and lakes, both natural and man-made, to make a splash. But despite the fun that might be available at such waterways, without proper precautions or basic knowledge of swimming and water safety, these revelers could risk drowning, as local authorities have warned.

At least six people died or were found dead in bodies of water in Shanghai last month, local media reports showed.

Two women in their 20s were reported to have drowned in the afternoon on July 12 at Dishui Lake, an artificial body of water in Pudong New Area, according to one report.

The Xinmin Evening News quoted a sanitation worker at the lake as saying that the two women were sitting on a rock on the riverbank when one fell into the water; the other plunged into the lake in an effort to save her.

The newspaper also reported a man in his 50s was found dead in a river at Songjiang Central Park 10 days later. Two days after that incident, the body of a 17-year-old boy was found in a river in Jiading district.

Then on July 30, two boys, aged 4 and 8, were found dead in two rivers in Songjiang district. It was reported that each was playing on the riverbank before falling into the water.

While swimming is popular in the summer, many Shanghai residents opt for natural rivers and lakes, as opposed to swimming pools. Popular swimming holes include Dishui Lake, Huating Lake and Zhangjiabang River.

On a recent visit to these areas, the Global Times found about six to 10 people swimming in each place. Few had flotation or safety devices.

At Huating Lake, a sign was posted saying: "deep water no swimming."

One swimmer at Huating Lake told the Global Times that he is a regular.

"I don't like to go to swimming pools. Swimming pools are so crowded, and water there reeks of chlorine," he said. "Also, swimming pools charge entry fees, while it's free to swim at the lake."

A swimmer enjoys himself in a river in Shanghai against the backdrop of a sign that reads "no swimming."

A man takes selfies while swimming in natural waters.

Swimmers ignore signboards and even an administrative staffer's warning against swimming in local rivers and ponds.

People of different ages have a good time swimming in natural waters. Photos: Yang Hui/GT