This year’s hotter, longer and more frequent heatwaves have been made much more likely by climate change. The summer of 2026 is on track to be the UK’s hottest ever – until, that is, an even hotter one comes along in the not-too-distant future.
The unusual heat and lack of rain have caused disruption, including transport issues, wildfires and hosepipe bans. But the disruption could have been much worse without the hard work of engineers both before and during the heatwaves.
From the rail network to data centres, here are three ways in which engineers keep everyday services running in the UK and elsewhere.
Rail engineers keep journeys on track
Many aspects of the UK’s rail network – including the rails, overhead power lines and air conditioning on the trains themselves – are put under severe pressure by high temperatures and blazing sunshine. Thankfully, Network Rail has an array of techniques used to minimise disruption.
Modern overhead lines use auto-tension systems, for example, to avoid hot lines expanding and sagging down. When necessary, temporary speed restrictions can reduce the risk of damage and any subsequent line closures.
On the rails, vulnerable ‘hot spot’ sections of track can be painted white to minimise absorbed heat, reducing the temperature by as much as 10ºC and preventing the steel from buckling.
Sensors – used on-train, on-track and in manual inspections – also play a vital role in monitoring track temperatures. Remote sensors fitted to sections of rail can share temperature readings with Network Rail workers every 15 minutes, as well as sending alerts if the rail crosses a threshold temperature. That data allows engineers to make smarter decisions, according to the infrastructure manager, such as only introducing speed restrictions on the precise sections that need them.
Nuclear engineers optimise cooling
While not as intimately tied to weather conditions as wind or solar, nuclear power is susceptible to heatwave disruption. In France, which gets about 70% of its electricity from nuclear, several reactors were shut down during extreme heat in June and July. Yesterday (11 August), a power plant near Dunkirk even turned off reactors due to a swarm of jellyfish – which are becoming more common due to warming coastal waters – clogging cooling equipment, according to Le Monde.
Heatwaves can also constrain nuclear generation at plants using river water for cooling, said François Le Scornet, an energy and climate tech consultant based in Grenoble: “If river temperatures are already high, nuclear plants may need to reduce output slightly… in order not to perturb the downstream ecosystems that can be sensitive to small temperature elevation.”
For engineers in the sector, solutions include the optimisation of cooling systems and the use of cooling towers with advanced designs, he said. The cooling system and towers at Civaux nuclear plant further cool water discharged into the Vienne river, for example, helping it continue operating during high temperatures.
“With heatwave intensification, cooling system design as well as water availability and thermal discharge rules will become increasingly important for nuclear operators,” Le Scornet said.
Building services engineers prevent overheating
Air conditioning is far from the only technology used to keep offices and other shared buildings cool. District cooling networks using water from rivers or lakes could offer a more sustainable way of doing things, while passive solutions such as natural ventilation and tree shading are even lower-intensity ways of minimising indoor temperatures.
‘Cooling rooftops’ – which collect rainwater and automatically spray it on to the buildings below during hot weather – could also reduce reliance on air conditioning, according to new research from the University of Manchester.
“Our study shows that harvesting rainwater from roofs and using it strategically for cooling could provide a practical way to reduce both energy demand and urban temperatures,” said lead author Dr Zhonghua Zheng in an announcement last week (5 August).
“What is particularly encouraging is that the benefits become even greater during hotter years, suggesting this approach could become increasingly important as the climate continues to warm.”
Some facilities, such as data centres, are particularly susceptible to high temperatures as they already require significant cooling during normal temperatures. Automated systems check seven-day forecasts for each site, according to Andreas Trenkle, director of technical operations for internet service provider Ionos, with alert thresholds set against each centre’s “local climate baseline”. Cooling systems and water reserves are inspected and tested before high temperatures hit, with redundant systems used to ensure consistent cooling in server rooms.
“A single fault doesn’t reduce cooling to the halls. It would take multiple failures across separate layers before room temperature moved,” Trenkle said.
“If it did, there are protections at both facility and hardware level. Automated thermal management responds first, then servers throttle and shut down to protect data and equipment before heat damage occurs. The design intent is that those protections never get used.”
Keeping centres running means company websites, shops and emails stay online during heatwaves, he added, preventing disruption to trading.
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