A young woman was so cold after a speedboat crash on the Thames that paramedics were forced to drill into her bone as they battled to save her, a court has heard.

Charlotte Brown was hypothermic with a body temperature of just 25C by the time she was pulled from the water by the RNLI in December 2015, jurors were told.

The 23-year-old had been thrown into the river near Wandsworth Bridge when a speedboat capsized during a champagne-fuelled first date with web designer Jack Shepherd.

Shepherd, 30, who lived on a houseboat in Hammersmith, is on trial in his absence at the Old Bailey.

He has denied Ms Brown's manslaughter by gross negligence.

The court heard his boat was speeding and neither occupants were wearing life jackets when it crashed into a log in the water and turned over while Ms Brown was at the wheel.

Shepherd was found clinging on to the upturned hull but Ms Brown was taken out of the water unresponsive.

RNLI rescuers performed CPR before handing over treatment to paramedics who had rushed to Putney Pier.

Giving evidence, paramedic Andrew Alcroft told jurors that Ms Brown was in cardiac arrest.

Medics drilled into the bone to administer fluid because they could not access her veins, due to the cold body temperature and cardiac arrest.

He said: "We were unable to get intravenous access because no veins came up."

Prosecutor Michelle Nelson asked: "You say that it was so cold you could not get access to her vein?"

Mr Alcroft replied: "Yes. There was no blood pressure because of the cardiac arrest."

Ms Nelson said: "You describe her as being hypothermic?"

The witness said: "Yes, with a temperature of 25 degrees it is a hypothermic temperature. Below 30 we describe as hypothermic."

Normal body temperature is 36.9 degrees.

The trial has heard that a post-mortem examination later recorded the cause of death as cold water immersion.

The trial continues.