We've recorded the temperature onboard a 38 bus between Grays Inn Road/Holborn and Essex Road, Islington this afternoon. Our Political Correspondent Simon Harris's tweets accompany each image.
On Friday, the Mayor Boris Johnson promised to fix the problem, and Transport for London claimed an 'army of engineers' would work throughout the weekend to get the air conditioning working.
But many commuters have complained that the top deck of the new bus for London is still "unbearable"
More top news
Pictures of today's events unfolding following a major security incident at the Houses of Parliament.
At least two people have died after a knifeman brought terror to the heart of Westminster.
The Cobra committee brings together government ministers with senior officials of the emergency services and security agencies.