It comes after emergency services were called to Ulley reservoir on Friday (May 28) after a teenage boy got into difficulty while in the water.
A body was later recovered from the water and although formal identification has not yet taken place, police believe it to be that of the teenager. His parents are receiving support from trained officers.
South Yorkshire Police and South Yorkshire Fire and Rescue said although the open water may seem inviting, freezing temperatures, hidden currents and debris underneath the water can all pose grave dangers.
Superintendent Cherie Buttle, of South Yorkshire Police, said: “[Friday's] incident was incredibly tragic, and my heart goes out to the boy’s family and loved ones – my thoughts are with them today.
“While I would encourage people to avoid speculation as to the circumstances surrounding what happened, I urge everyone to be careful while enjoying the bank holiday weather. Please be safe.”
South Yorkshire Fire and Rescue's area manager Stewart Nicholson added: "Too many young lives are needlessly lost in open water every year. Our message couldn't be clearer - please, please stay out of the water and stick to swimming pools or organised swimming groups instead."
They said there are four things to consider when around water:
- The water might be much deeper and much colder than you expect
- Even if the weather is warm, cold water can dramatically affect your ability to swim
- There may be unexpected currents which can pull you under
- There can be hidden rocks, rubbish or reeds which can cause you to become tangled or cause injury.