`You fall you're dead,' the voice inside my head told me. I was balancing on a knife-edge ridge, sheer drops either side of me. The cold was chilling me to my core. But I could not give up. I had to focus, The summit was within reach. Everest: the highest mountain in the world and also one of the most dangerous. On May 24 2007, Tori James made history when she became the first Welsh woman, and youngest British woman, to climb to the summit of Everest. It was an amazing achievement for the petite farmer's daughter from Pembrokeshire. In Peak Performance Tori shares the inspiration and drive that helped her to succeed in reaching the `rooftop of the world'.