PEOPLE have been warned not to swim in reservoirs during the hot weather.
United Utilities said: "The weather may be hot but the reservoirs are NOT. Please remember reservoirs are NOT safe places to swim.
"The water is extremely cold, even on the hottest of summer days.
"Cold enough to make you panic. Could enough to make your arms and legs numb which means you can't swim."
Lee Heard, from the Royal Life Saving Society, said open-water swimming in hot weather placed people at risk of cold water shock.
"The difference between air temperature and water temperature can literally take your breath away.
"It is silent, invisible and deadly.
"Water can also hide debris, strong currents and sudden changes in depth that can catch out even the strongest swimmers."
The Royal Life Saving Society said that about 402 deaths a year in bodies of water were "entirely preventable."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here