Siblings from Witney will be spending their Christmas Day taking a cold plunge -- to raise funds for charity.

Lucy and Jack prepare for the cold dip

When Lucy Chance-Arkell was born 10 weeks' premature, she weighed under three pounds and spent four weeks in the Silver Star Unit at the John Radcliffe Hospital in Oxford.

Lucy's younger brother Jack -- pictured with her -- was also premature and spent time in the same hospital unit.

On Christmas Day, Lucy, now 10, and Jack, eight, who live in Thorney Leys, Witney, will be diving into the Irish Sea to raise money for the unit.

Their mother Anna-Marie said: "They've always wanted to do something for the Silver Star Unit.

"The staff are brilliant."