Passengers have been forced to evacuate trains in south London as temperatures soared above 30C (86F).
A fault on a train near Loughborough Junction brought all services in the area to a halt, three of them outside station platforms, Thameslink and Network Rail said in a joint statement.
“Without power and air conditioning on such a hot day, we pulled all resources from across Sussex and Kent to get personnel on site to safely evacuate passengers as quickly as possible along the track,” it said.
Angela Lewis, a Gatwick-bound passenger, said it was “a bloody nightmare”. Thameslink apologised to those affected for the “difficult and uncomfortable experience”.
The incident began at about 10:40 BST with the evacuations of the first two trains completed at about 12:20 and the third at about 13:10, a spokesperson said.
They added that due to engineering works, this was the only route taking Thameslink services south out of London and “and disruption is expected into the evening”.
Writing on social media, Ms Lewis said passengers had been left on the train for about two hours before being removed.
“Some people had luggage and infants, had been trying to get to Gatwick,” she said.
Ms Lewis added that some had missed their flights due to the disruption, adding: “Who will compensate them?”
Heatwave peak
The heatwave was forecast to bring temperatures of up to 33C (91F) to the capital on Saturday, and drew thousands to its lidos and bathing ponds to cool off.
But warnings over heat-related illnesses and remaining safe while swimming in open water have been issued as London Ambulance Service (LAS) predicted a surge in 999 calls.
Meanwhile, researchers at the London School of Hygiene and Tropical Medicine and Imperial College London (ICL) released a study that used historical data to forecast the capital could see 129 excess deaths related to this week’s hot temperatures.
Across England and Wales, excess deaths from Thursday to Sunday are estimated at about 570 people.
By lunchtime, the temperature at Heathrow Airport had reached 31C (88F).
Researchers said their assessment highlighted how extreme heat posed a growing threat to public health in the UK.
Dr Garyfallos Konstantinoudis, lecturer at the Grantham Institute at ICL, said: “Heatwaves are silent killers – people who lose their lives in them typically have pre-existing health conditions and rarely have heat listed as a contributing cause of death.
“This real-time analysis reveals the hidden toll of heatwaves and we want it to help raise the alarm.”
He added that heatwaves were an “underappreciated threat” in the UK.
