WHILE trudging through an Asian rainforest or resting breathlessly at the top of an Indonesian volcano, Oliver Nash had no idea one day his adventures would help raise money for the hospital which saved his life.

The 32-year-old has penned a children’s book based on his adventures as a young man – and he’s hoping the work will help him raise £10,000 for Great Ormond Street Hospital.

Oliver should know just how amazing and worthwhile the world-famous London hospital is because it saved his life when he was a young boy.

When Oliver, of Oldwyk, Vange, was just seven, he was diagnosed with a Wilms’ tumour, an aggressive kidney cancer which only affects about 70 children in the UK every year.

He spent years being cared for at Great Ormond Street and is under no illusion he owes his life to the hospital.

“There’s no doubt about it, if it wasn’t for the doctors and the medics at the hospital, I wouldn’t be here today,” said Oliver, a former pupil of King Edward Grammar School, in Chelmsford, “It’s not just the medical side of things, the hospital is so good at. I remember how the doctors would come up to me in my bed and I’d charge them 10p to examine me.

“They’d always hand the money over and laugh.

“When you are a child and you’re in that situation you need doctors and nurses who really care about you, and at Great Ormond Street they do.”

Oliver has recovered from cancer now. However, the disease has left him with an ongoing heart problem.

“I still see a lot of the Great Ormond Street doctors now, but at the adults hospitals in London where I’m a long-term outpatient because of my heart condition,” he added.

Oliver’s book, the Primate Puzzle, is based on his travelling adventures.

When he was in his mid-twenties, Oliver decided to quit his job in the City and travel. He trekked through the rainforests in Borneo and, upon learning the plight of some of the country’s animals, decided to try to make his book more educational.

Filling several notebooks with detailed observations and with hundreds of photos to back them up, Oliver recorded an extraordinary two-year journey across south-east Asia, Australia and New Zealand.

While in Borneo, Oliver started work on a short story for his friend’s daughter Amy Applegate, the main character in the book, but soon realised there was a potential children’s educational work evolving.

“It was quite lonely travelling and when I was in the rainforest, or in some tranquil place, I’d have all the time in the world to write,” said Oliver.

The finished product was the Primate Puzzle, an educational adventure for eight to 16-year-olds.

The book is illustrated by artist Bethanie Cunnick and can be bought as an e-book or hard copy.

It aims to educate children and their parents about the plight of endangered animals and the importance of environmental conservation.

Oliver said: “What started out as me coming up with an amusing story for a friend’s daughter, has turned into something special and a way of me giving something back to Great Ormond Street. It turns out Amy loved the book and so I’m hoping other youngsters will want to delve into it as well.”

Oliver is now in the process of getting the Primate Puzzle recorded into a talking book, so it can be played over hospital radio stations, including Basildon Hospital, He added: “I’ve always felt I owed Great Ormond Street everything I have. Its doctors saved me when I had childhood cancer and keep a watchful eye on me even today at the age of 32.

“I hope my first book will help them to help other children like me.”

The book, which costs £7.50, has already raised more than £2,000. To order the book, visit www.justgiving.co.uk/theprimatepuzzle