The concourse at Waterloo was packed with frustrated commuters this evening, as services were affected by the hot weather.
South West Trains put speed restrictions in place between Clapham Junction and Waterloo - because the tracks were struggling to cope with surface temperatures approaching 50 degrees Celsius.
Trains were limited to 20 miles an hour, with many services delayed, cancelled or altered.
More top news
A lamp in the tower which houses Big Ben is to be switched off for the first time in more than 70 years.
Sir Bruce entertained audiences for more than seven decades.
Work in the tower will also pause over the bank holiday weekend.