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"
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The NHS said errors were extremely rare and it was vital they are investigated when they happen.
The piece will go on public display at Sotheby's in London, a mile away from the Palace of Westminster, from September 28 to October 3.
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