PEOPLE are putting their lives in danger by swimming in North Yorkshire’s reservoirs, according to a water company.

Yorkshire Water has responsibility for 120 reservoirs across Yorkshire and the Humber, including Cod Beck, near Osmotherley.

The company is aiming to remind people of the dangers of taking a dip in reservoirs during National Water Safety Awareness Week, which started on Monday.

The company is still receiving reports from passers-by of people swimming in its reservoirs, and with the prospect of warmer weather ahead, bosses are urging people not to be tempted to take a dip in its waters.

Reservoirs may seem like a good place to take a swim to cool down but they are dangerous because of cold water temperatures and strong under currents beneath the surface.

When fatalities occur, it's often the temperature of the water which is the most significant factor.

Reservoirs are deep and the water in them doesn't flow like in rivers or the sea, so the temperature rarely rises much above 12C.

Geoff Lomas, the company’s recreation and catchment manager, said: "What began as a day out in the sunshine can turn to tragedy within minutes if you decide to take a dip.

"It really doesn't matter how well you can swim, as it's the cold which can kill you.

"Most people won't realise that, as soon as your body feels the shock of cold water, its natural defences kick in.

"The first sign of trouble is hyperventilation but, if the swimmer stays in the water, the body will gradually shut down to protect the vital organs and muscles will go into cramp.

"The victim will be unable to remain afloat and will sink below the surface and, if help doesn't arrive within seconds, they will drown."

Even if the alarm is raised quickly, it can be minutes before emergency services arrive at the scene and, even then, they may not be able to enter the water until specialist equipment arrives.

Yorkshire Water has worked with the Hambleton Community Safety Partnership to develop a hard-hitting DVD which re-enacts a drowning and the response by police, fire and ambulance services.

More details about the Dying To Be Cool campaign are available online at yorkshirewater.com/safety