Swimmers are risking infection and injury if they take a dip in Oxfordshire's rivers to cool down this summer.

A range of conditions can be picked up in rivers - from the deadly Weil's Disease found in rats' urine, to heart attacks caused by swimming in cold water.

But swimmers are more likely to suffer from stomach upsets and are now being urged to think twice before using Oxfordshire's rivers as a place to cool off.

Hassan Hussain, 15, a pupil at The Cherwell School, Oxford, drowned in the River Cherwell near the University Parks after he strayed into a deep section just metres from the bank.

There are no warning signs at the spot and Oxford University, which is responsible for the Parks, says it will investigate ways to make people aware of the dangers of swimming in the river, but has not revealed details or a timescale for this.

Despite the tragedy, people have been spotted jumping into the river from bridges, including Donnington Bridge.

Susanne Furman-Lee, of the Health Protection Agency, said they are not only at risk of drowining: "You can get infections, including gastroenteritis, from swimming in rivers. So it is important to follow basic hygiene advice and wash your hands before eating.

"People do need to recognise that the river is a source of infection."

According to the Environment Agency and the Health Protection Agency, diseases in rivers include cryptosporidiosis spread by rodents which can cause diarrhoea and abdominal pains for up to three weeks.

Beaver Fever, or Giardia Lamblia, can also cause diarrhoea, dehydration, abdominal pains, weight loss, headaches and high temperature.

Swimmers in rivers with open cuts or grazes risk contracting Weil's Disease from rats' urine. The disease, which leads to stomach pains, can be fatal or lead to liver and kidney damage if not treated.

Algae in rivers can cause diarrhoea, and toxic blue-green algae causes skin disease, eye irritation and liver damage if swallowed.

A host of other infections and rashes can be caught through sewage and farm slurry released into rivers.

Despite the recent sunny weather, the temperature of the water can also be a killer.

Unsuspecting swimmers can suffer cold shock, when cold water rushes up the nose cooling the brain, hypothermia, cramp and heart attacks caused by dips in temperature.