Sudbury common lands ranger Adrian Walters has reminded people to be careful and not to jump or dive into the River Stour this summer.
As temperatures rise, Mr Walters said it is important that people do not put their lives – and others – at risk.
He said: “Someone drowning or getting into serious difficulties in the River Stour is always a concern during the summer.
“As it gets hotter, the temptation to dive into the water can become almost irresistible, not only on Friars Meadow but at the Salmon Leap and the Floodgates Pool.
“Following a sad incident at Brundon a number of years, ago we put up signs to warn people that the river can be potentially dangerous.
“Winter flooding brings all kinds of debris, including tree trunks and large branches, which can create underwater hazards.
“It is very important that people do not dive or jump into the water because there may be hidden obstacles.
“Even a substantial amount of aquatic vegetation can pose a risk and induce panic in less confident swimmers.
“The shock of entering cold water can also be an issue, particularly once ground water is being pumped into the Stour rather than warmer water from the river Ouse.
“It is great to see people out enjoying themselves on the riverside but they should never throw caution to the wind. The simple message is to always think about the risks and stay safe.”
The Royal National Lifeboat Institution is calling on the people to fight their instincts if they come into trouble and remember one simple action – floating.
Sudden immersion in cold water puts people at severe risk of suffering cold water shock, which triggers the instinctive but life-threatening reaction to gasp uncontrollably and swim hard, which can quickly lead to drowning.
The Royal Life Saving Society UK’s deputy director of education and research, Mike Dunn, added: “Open water sites have many unseen dangers that can catch even the best swimmers unawares.”