Network Rail today imposed speed restrictions on some of the busiest commuter routes across Britain because of the soaring temperatures and its effect on the tracks.
Services between London and Birmingham will also be reduced from half hourly to hourly, with a 60mph limit imposed along the West Coast main line from Euston to Crewe and the cross country network.
A 60mph restriction has also been imposed across southern England, from 2 p.m. until early evening, causing "minimal effect" due to the relatively slow speeds currently in place on these routes.
Routes from London's Liverpool Street to Chelmsford and Norwich will also be affected.
Peter Henderson, Network Rail projects and engineering director, said: "Our first priority is always to run a safe railway. "With air temperatures expected at over 30 degrees in some areas today, we feel it is necessary and sensible to impose these speed restrictions.
"With temperatures dropping in the early evening, the restrictions are lifted. "This obviously varies from location to location but tends to happen between 6 p.m. and 8 p.m.", he said.
PA