LONDON — England on Monday was facing the possibility of serious disruption to its transportation networks as temperatures were poised to creep to unprecedented new highs.
Flights into and out of one of Britain’s busiest international airports were halted for much of the day after a “surface defect” caused by high temperatures was identified on the runway. Footage from London’s Luton Airport showed engineers repairing a roughly 15-foot-by-10-foot section of the tarmac. The airport reopened on Monday evening after work was completed.
Temporary speed restrictions were in place over large portions of Britain’s rail network, including on London’s tube system. Entire lines preemptively canceled service over fears that the extreme temperatures forecast could cause rails to buckle. And bold red warnings were posted in stations and on social media urging people to reconsider their trips.
But despite warnings to only take the most necessary journeys and guidance urging potential commuters to stay at home, many Londoners felt they had no choice but to use the city’s tube network and other trains on Monday morning.
Rufus Cameron, 26, who lives on the third floor of a shared house in north London, had decided to escape the heat of the city for his parents’ home in the south of England and was waiting for a train on Monday morning.
“Our flat is hot, outside it’s hot, it’s all a bit much,” he said. “In England, we have no idea how to deal with this kind of heat.” While he said he was worried about potential delays to the national rail service that would take him home, he hoped that leaving before the temperatures rose too steeply would spare him any issues.
“But what can we do with the infrastructure that we have in England,” he added. “It’s not built for this.”
In London, where some of the most extreme temperatures are expected — Tuesday’s forecast predicts a high of 103 degrees Fahrenheit — a number of tube lines had service suspended on Monday and Tuesday, according to a statement from Transport for London, which operates the network.
Just 40 percent of the Tube network has air conditioning, and Transport for London advised passengers to carry water and considering timing trips for cooler parts of the day.
National rail services were also bracing for disruptions to thousands of miles of steel tracks, which absorb heat easily and can buckle, causing serious delays. Steel rails expand when heated and can push against adjacent pieces of track, which can also damage equipment that detects where trains are to keep them a safe distance apart, according to Network Rail, which owns and repairs the railway infrastructure in England, Scotland and Wales.
In a statement, the company warned of delays, cancellations, and last-minute changes to train services on Monday and Tuesday. It also closed the entire East Coast Main Line, which runs between London’s King’s Cross Station and York and Leeds, for Tuesday afternoon.
“Closing the line to traffic is always a last resort but it is the right thing to do to keep people safe on Tuesday given the unprecedented heatwave forecast,” Sam MacDougall, the operations director for Network Rail, said in a statement. “The forecast temperatures are well above those which our infrastructure is designed, and safety must come first.”
The trains’ speed was also being limited on Monday, a move that would limit the number of trains running and extend journey times significantly, Mr. MacDougall said, urging passengers to “only travel if absolutely necessary.”