Transport for London is advising customers to only travel if absolutely necessary, due to the high temperatures forecast for the capital.
The Met Office has issued its first ever red warning for high heat for parts of the UK, including London, with temperatures forecast to reach 40C.
Temporary speed restrictions will need to be introduced on parts of the Tube and Rail network on Tuesday July 19 as a precaution, which will mean a reduced service and could mean journeys take longer than usual.
Very hot temperatures can affect rails, overhead power lines and signalling equipment.
TfL is also inspecting the air conditioning units on the Tube trains that cover 40 per cent of the Tube network, the trains on the Elizabeth Line and London Overground as well as the air cooling units on double-deck buses to ensure they are functioning well.
Passengers making essential journeys are advised to check before they travel, to carry water with them and not to board TfL services if they feel unwell.
If they do feel unwell, they should get off at the next stop and contact a member of staff or speak to the bus driver.
A number of Tube, rail and bus stations across the transport network have water points where customers can refill their water bottle when travelling, as part of the Mayor of London’s network of more than 100 water fountains around the city.
Andy Lord, Chief Operating Officer, TfL said: “Due to the exceptionally hot weather that is expected next week, customers should only use London’s transport network for essential journeys.
“If customers do need to travel, they should check before they travel as we are expecting there to be some impact to Tube and rail services as a result of temporary speed restrictions we will need to introduce to keep everyone safe.
“It is also vital that customers always carry water at all times with them when travelling.”
Image courtesy of TfL