The sun-facing side of the building acts as a mirror as the concave surface focuses all light on a single spot on the ground. Skyscraper? On reflection it’s more like a 37-storey barbecue: the city tower that can melt cars. Every day City hedgefunders race along the pavement to avoid being toasted. Even on a relatively cloudy day it was possible to fry an egg on the pavement underneath the Walkie Talkie Tower.