As temperatures rise across the UK, the public conversation often focuses on whether Britain is physically equipped to cope with extreme heat. For employers, developers, infrastructure operators and business leaders, the question is whether they are legally prepared.

The UK does not currently impose a maximum legal workplace temperature and that can potentially create a false sense of security. Employers remain under clear statutory duties to ensure, so far as reasonably practicable, the health, safety and welfare at work of both their employees and anyone affected by what the employer does. They must assess workplace risks and put in place control measures. The Health and Safety Executive (HSE) has made clear that risk from heat can arise not only from air temperature, but also from humidity, work rate, ventilation, heat sources and clothing or PPE.

This is no longer a theoretical risk

The UK recorded 40.3°C for the first time in July 2022 during what the Met Office described as an unprecedented heatwave and a marker of the UK’s changing climate. The same year was the UK’s warmest on record, with Met Office analysis finding that both the record warm year and the July heatwave were made more likely by human-induced climate change.

Extreme heat is no longer simply an unusual summer inconvenience. Researchers from Imperial College London, the Met Office and the London School of Hygiene & Tropical Medicine estimate that more than 2,700 people may have died from heat-related causes during the heatwaves experienced across England and Wales in May and June 2026.

For businesses, the issue is therefore shifting. Extreme heat is a foreseeable workplace, operational, infrastructure and governance risk.

No maximum temperature does not mean no legal duty

There is no maximum workplace temperature established in law in the UK. The Workplace (Health, Safety and Welfare) Regulations 1992 require indoor workplaces to be maintained at a “reasonable” temperature, but do not specify a maximum. Employers are also subject to broader duties under the Health and Safety at Work etc. Act 1974 and the Management of Health and Safety at Work Regulations 1999, including the duty to assess risks and implement appropriate control measures.

Extreme heat falls squarely within those duties. For construction, logistics, manufacturing, transport, healthcare and infrastructure businesses, the risk profile is often more complex.

While the UK currently has no legal maximum workplace temperature, the issue is attracting increasing political and regulatory attention. Recent proposals to introduce a statutory upper temperature limit for workplaces reflect growing concern about the impact of extreme heat on workers and the wider economy. Whether or not such reforms are ultimately adopted, employers should not assume that the absence of a maximum legal temperature removes the need to assess and manage heat-related risks.

The core legal question is unlikely to be whether an employer could eliminate heat risk entirely. It is whether the organisation can show that it identified the risk, assessed who might be harmed, implemented proportionate controls and kept those measures under review.

Heat is now an infrastructure resilience issue

The legal risks associated with extreme heat extend well beyond the workplace.

Transport infrastructure provides one of the clearest examples. During the July 2022 heatwave, Network Rail launched an Extreme Heat Taskforce after abnormal measures were needed to protect passenger safety.

Climate resilience is not just a question of engineering; it is a question of procurement, financing, contractual allocation of risk, regulatory compliance and long-term asset stewardship. It's essential for businesses to start considering these issues.

For infrastructure operators and investors, heat-related disruption can create consequences across whole systems: delayed services, supply chain failures, customer claims, maintenance challenges, performance penalties and disputes over who bears the cost of adaptation.

When heat starts affecting contracts

Heatwaves are often treated as operational events but they increasingly need to be treated as contractual events. Heat-related disruption can affect construction, logistics, manufacturing and real estate projects, with the legal implications ultimately depending on the contract.

Parties may need to consider force majeure clauses, extension of time provisions, relief events, change in law clauses, service level commitments, maintenance obligations, business continuity requirements and insurance arrangements. The key issue is whether the relevant risk has been anticipated, assessed and allocated clearly.

That analysis is changing because extreme heat is happening more frequently and for longer. The Met Office has said that UK temperature extremes are changing faster than average temperature, and that a year like 2022 could become an average year by the middle of the century under a medium emissions scenario.

If heatwaves are no longer rare, employers and contracting parties may find it harder to treat them as wholly unexpected events. Businesses entering long-term construction, infrastructure, outsourcing, logistics or facilities management arrangements should therefore be asking whether their contracts are still fit for the climate conditions in which they will be performed.

Property owners face a new climate reality

For many years, climate-related property due diligence has focused heavily on flood risk. That remains important, but overheating risk is rapidly moving up the agenda.

The Climate Change Committee has warned that the UK's preparations for climate change remain inadequate, with growing risks for infrastructure, buildings, productivity and supply chains. For commercial property owners, investors, developers and occupiers, this raises practical legal and commercial questions. Can a building maintain safe and productive conditions during periods of prolonged high temperature? Are cooling, ventilation and shading strategies adequate? How will retrofit works interact with energy efficiency obligations? Could overheating affect occupier satisfaction, asset values or future leasing strategy?

These questions are not purely technical. They may arise in development agreements, leases, warranties, acquisitions, financing arrangements, planning strategy and ESG-related disclosures.

Preparing today for tomorrow’s extremes

Britain’s latest heatwave will pass. The legal and commercial questions it raises will not.

Businesses should be asking:

  • Have we assessed the risks extreme heat presents to our workforce and anyone affected by what we do, including outdoor workers, those wearing PPE and those with vulnerabilities?
  • Are our risk assessments, policies and emergency procedures up to date?
  • Do our contracts allocate heat-related delay, disruption and cost clearly?
  • Are our buildings, sites and operational assets resilient to prolonged high temperatures?

At Gowling WLG, our teams advise clients across employment, health and safety, real estate, infrastructure, construction, commercial contracts, environmental law, regulatory compliance and disputes. Our work on transport resilience, climate adaptation, environmental regulation and contractual risk allocation allows us to help clients approach heat risk as a joined-up legal and strategic issue.  

Preparing for extreme heat requires more than an operational response. It demands a joined-up approach to legal risk, resilience and long-term planning. To explore the issues raised in this article, please contact Andrew Litchfield, David Lowe or your usual Gowling WLG contact.