Last month he completed a 51-day, 1,600km trek across the Mongolian Gobi Desert,.
The world's fifth largest desert - Asia's largest - poses a gruelling challenge with its rapid fluctuation of temperatures over a single day, ranging from 5degrees Celsius to 45 degrees.
Christopher, who is originally from the Netherlands, and moved to Hong Kong with his family when he was a baby, joined 13 other international adventurers on the Gobi Crossing Expedition.
Led by British desert explorer Ripley Davenport, the trekkers battled severe dust storms, blizzards and heatstroke to raise funds to educate Mongolian children.
Christopher has been organising charity events since he was 15. He founded Youth Endurance Network, a group that runs activities such as last December's "24 Hour Race to Stop the Traffik", which involved about 180 Hong Kong secondary students running in a relay to raise awareness of human trafficking.
"At 15, when I was in boarding school in the UK, my classmates and I were talking about summer plans. And I said, 'Why don't we do a massive walk for charity?'"
Some people laughed at his idea, but within a few months he and a friend had finished their first two-week charity walk.
Christopher has continued doing walks and sports for charity ever since. "It gives us a purpose in life, which many students, especially those that are from middle-class families, lack," he says.
The trek over the desert began on May 25; every day the team began walking at 5am and continued until 11pm, with a 45-minute break for lunch.
"It was the toughest thing I've ever done in my life," said the 19-year-old student, who has just left Li Po Chun United World College. "After the first 12 miles, I felt there was no way I could finish it.
"Walking on sand was hard; there were twisters [tornados] coming out from nowhere. When we were halfway through the trek, I lost track of the days, it was raining and I felt really homesick. It's not about physical but mental strength."
The day he rode on a camel for the first time and looked out at the vast horizon proved life-changing. "There was a magical moment of silence," he says. "I felt vulnerable looking at the landscape - thinking that life has a much bigger meaning. It was a spiritual experience.
"There's such a great respect in the [desert] culture. People are very naturalistic and laid back. I'm amazed by their deep respect for the balance in life. It makes me feel more relaxed about myself and things."
One special memory was being taught to herd camels by local teammate, Albhek. "It was not easy. Camels are not the most agreeable animals. They are very strong and it's hard to gather them back when they run away."
Christopher is now back in Hong Kong, but is already planning to return to Mongolia. In December, he will stay with Albhek's family in Bayan-Ulgii and herd animals for five months.
"The trip has opened a new door for me to foreign territories," Christopher says.
"I'm intrigued by the old, traditional way of living in Mongolia. I want to see what it's like to live like a nomad - be spontaneous in life."
Learn more: www.gobi2011.com