The construction industry has adapted working practices to continue building through the unseasonably hot weather last week.

Clients and contractors across the UK switched to established protocols to ensure workers could continue with key jobs while staying safe in the heat.

Thermometers hit almost 35ºC in London on Monday (25 May), setting a new spring record that was then reportedly beaten on Tuesday with 35.1ºC.

Heatwaves are expected to be formally declared in many areas as the prolonged period of high pressure continues.

The UK’s biggest contractor Balfour Beatty was among those activating established measures for working in extreme conditions, Construction News understands.

This meant all its teams receiving briefings before starting each day, and site leaders reinforcing guidance on managing risks such as dehydration, sun exposure and heat-related illness.

The contractor has encouraged restricted work periods to allow individuals to cool down and rehydrate at regular intervals, and provided staff with suncream as well as water.

Network Rail said it had adapted “how and when work is carried out” to keep people safe while attending to its infrastructure.

Special protocols for heatwaves

“We have well-established hot-weather working arrangements in place to protect staff, including ensuring access to water and the use of suncream,” said a spokesperson.

Adapted work patterns included “avoiding the hottest parts of the day and allowing additional breaks where needed”, they added.

British Land is also understood to have taken extra precautions for construction workers.

Across its developments, teams have been monitoring the weather and adapting welfare provisions accordingly.

This has led to measures such as additional water points, suncream on offer in welfare areas, additional welfare locations and temporary rules such as banning lone working.

A National Highways spokesperson said: “We take the wellbeing of everyone working on our roads seriously, and we’re incredibly grateful to those working in challenging weather conditions to help get everyone home safe and well.

Heatwaves pose health risks

“For our colleagues, this means keeping a close eye on conditions, carrying out heat‑risk assessments, and making sure people have access to drinking water, sun protection and regular breaks.

“While our supply chains are responsible for the health, safety and welfare of their workforce, we work closely with them to support safe working during hot conditions.”

EDF said temperatures formed part of risk assessments for construction duties on the Hinkley Point C nuclear plant.

“For those working in outdoor environments, supervisors ensure teams have regular breaks and opportunities to hydrate,” said a spokesperson. “We have a wide range of water stations around the site, available to all.

“There are reminders about sunscreen and for some roles, such as banks-people working outside directing plant and vehicles for longer periods, caps with neck protection are provided as another measure to protect against the sun.”

They added that much of the work on the Somerset site was now taking place inside buildings.

“Concrete structures on site are staying relatively cool during the day. In areas like the turbine halls and galleries, working temperatures in recent days have been very good and in many places cool compared to weather outside.”

The prime minister’s office said on Tuesday (26 May) that it was not looking at setting a maximum legal temperature for workplaces.

This comes after the Climate Change Committee last week called for a national maximum outdoor working temperature in response to global warming.

In the meantime, the Health and Safety Executive reminded employers this week that they “must ensure workers are protected during hot weather”.

“There’s no law for maximum working temperature, or when it’s too hot to work, because every workplace is different,” said the body.

It pointed to guidance on its website, which says health and safety laws require “comfortable” temperatures and “fresh air”.

It also says working outdoors in hot environments for long periods can “affect workers’ health”.

High temperatures are expected to continue throughout this week before cooler, wetter weather sweeps in at the start of June and the meteorological British summer.

Source: https://www.constructionnews.co.uk/health-and-safety/contractors-adapt-working-practices-as-uk-swelters-27-05-2026/