The devastated mother of a fit and healthy 13-year-old schoolboy who caught a cold during a Christmas holiday and died just days later from sepsis has told how she wants to use his story to raise vital awareness.

Oliver Darlington was enjoying a holiday in New York with mum Rachel Flynn, 34, step-dad David and sister Holly, seven, when he came down with cold-like symptoms.

Despite his cold, the "cheeky" teenager had been running around Central Park on December 29 before flying back to the UK the following day.

However he became seriously ill in the early hours of December 31 and was rushed to hospital.

Tragically he suffered a cardiac arrest and died three days later on January 3.

Mum Rachel from High Wycombe said they didn't see anything "out of the ordinary" when they returned home and just thought Oliver was a bit tired from the jet lag.

She said: "It's terrifying how quickly it can go from thinking he maybe had a stomach bleed to being told your child might not make is unbelievable that's why I want to raise awareness.

"On the holiday, he was his usual self but he had a bit of a cold, a bit of a cough but it was nothing out of the ordinary.

"We flew back overnight.

"He was still feeling a bit poorly but we put it down to jet lag. He was running around Central Park the day before."

On December 30, Oliver and his sister Holly went to stay with their dad Tom Darlington, 39, to have their second Christmas together.

Oliver, who was a Wycombe Wanderers fan, also has a younger brother called Jack, three, and a step-brother Ryan, nine.

In the early hours of the morning however, Oliver became violently sick and had diarrhoea.

Tom, who is head of planning at a logistics company, said: "He spent most of the time lounging on the sofa then at about 8.30 in the evening he went to bed.

"Then he called out at about 3.45am and he was really poorly. I got up straight away and started looking after him, I instinctively knew that something was not quite right."

His wife called 111 and soon after an ambulance arrived to take Oliver straight to Stoke Mandeville Hospital.

Tom continued: "What I find quite scary is I've read stories where people have symptoms for days but Oliver didn't have that, he had hours.

"I was watching him deteriorate in front of my eyes minute by minute."

Rachel, a solution implementation specialist, said: "The first time they mentioned sepsis was in the ambulance. It's one of those things that you've heard of and know it's not good.

"When I got to hospital, he was still conscious and talking but while I was there he developed a rash on his feet.

"He had a seizure about five minutes after I got there and then his heart started to go.

"We knew something was wrong. They just said he was very poorly but that they didn't know exactly what it was."

Sepsis is a potentially life-threatening condition caused by the body's response to an infection.

The parents were told Oliver had to be transferred to Southampton hospital to give him the best chance of survival.

Rachel said: "A team came down to assess him and we knew then how serious it was. He was probably the sickest person in the hospital.

"We were told he might not make it out of theatre but we had to do it because that was his only chance of survival to get him to Southampton."

Once at Southampton Hospital, Oliver was put on an Extracorporeal Membrane Oxygenation (ECMO) machine which removes the blood before oxygenating it and putting it back.

Rachel said: "His organs were starting to fail and you even started to see his limbs deteriorate.

"It was touch and go for a lot of the time and then on Thursday he was actually improving quite a lot. By 6am Friday morning it had completely flipped."

Tragically, a CT scan showed how Oliver developed brain damage and the decision was then made to turn off his life support machine.

The family have since vowed to raise awareness of sepsis following Oliver's death to try to ensure no other family has to go through what they have gone through.

Rachel said: "It's the little habits like when I ring Holly when she's at her dad and I think about asking for Oliver and then it hits you all over again.

"He was very cheeky, very funny, he had quite a mature way about him but he was still silly and still very much a teenager!

"He loved football and his scooter he was just lovely to be around. He was so caring and empathetic.

"Oliver wanted to help people so we are using his story to help others, it's what he would have wanted us to do. Even if we can help one person.

"It's about asking the question because people are aware of cancer so they go to the doctors and think could it be cancer but we want people to ask whether it could be sepsis too."

Tom added: "Whilst we did everything we could for Oliver at no point did we ever believe that it was sepsis.

"He had so much life and he had so much to look forward to."

A fundraising page in memory of Oliver and for UK Sepsis Trust has so far raised more than £9,000.

If you would like to donate you can visit the page here: