M. Williams : As an explorer it’s easy to think that you are invincible, and can meet any challenge in the world. But there are moments when you are brought back to earth with a bump. Such a moment occurred to me last year, as I was climbing the Himalayas.

We had been trekking for almost 2 weeks and we were half way up of the mountain, when suddenly one of my colleagues in front screamed ‘Watch out!’. I leapt to my right and the ground trembled beneath me, and snow was rushing past in an avalanche. I instinctively clung on to my ice pick, in the hope of slowing down my slide. Luckily, I hit a patch of hard ground, and was able to get to safety. Through the next 2 weeks there were several major avalanches and despite this, two of my colleagues decided to continue the climb.

A week later, they were both dead. This brought home to me how fragile we are in the face of the forces of nature. We sometimes forget just how dangerous this world can be.