British tycoon Sir Richard Branson's socialite son had to be rescued from the Matterhorn in Switzerland on Wednesday (03Sep14) after becoming stranded at the summit.

Sam Branson was participating in the Big Change Virgin Strive Challenge, and climbed to the top of the mountain after previously running three marathons, rowing across the English Channel and cycling to Vervier in Belgium.

But he fell ill and a helicopter rescue crew had to fly in to help him.

The adventurer's dad Richard tells Cnbc's Halftime Report, "Today, three of them did manage to get to the top of the Matterhorn, and sadly my son, who did get to the top, suffered extreme altitude sickness, but made it and had to be helicoptered off... He's fine. Everybody's fine."

"But he managed to get from the U.K. to the top of the Matterhorn, and they raised tons of money for young people in the U.K. who had issues, and completed a great mission."

Branson admits it's odd not being the family's top risk taker and adventurer: "It's quite strange now seeing my son off rather than him seeing me off."