Workplace Temperature: Why There's Still No Legal Maximum, and What's Changing

Every summer, the same question resurfaces in offices across the UK: is there a temperature at which staff can legally refuse to work? The honest answer, as of 2026, is no — there is still no statutory maximum workplace temperature in UK law, only a general duty that conditions be "reasonable." That gap is now under active review, and it's worth employers understanding both where the law currently stands and where it may be heading.

The current legal position

Workplace temperature is governed by the Workplace (Health, Safety and Welfare) Regulations 1992, specifically Regulation 7, and its Approved Code of Practice. The regulation requires that temperatures in workplaces during working hours be "reasonable," and the accompanying guidance commonly cites a minimum of 16°C for most indoor work (lower for physically demanding roles). Critically, the regulation sets no equivalent maximum figure. "Reasonable" is deliberately open to interpretation based on the nature of the work, the workplace, and individual circumstances, which means there is no fixed number an employer can point to, or that an employee can invoke, to say a workplace has become unlawfully hot.

This doesn't mean employers have no obligations once temperatures rise. The general risk assessment duty under the Management of Health and Safety at Work Regulations 1999 still applies, and heat stress — dizziness, fatigue, reduced concentration, heat exhaustion in more extreme cases — is a foreseeable risk in a poorly ventilated or south-facing office during a heatwave. An employer that does nothing at all as conditions become genuinely hazardous is still exposed under the general duty, even without a specific numeric threshold to breach.

Why this is under review now

HSE confirmed in July 2026 that it is reviewing the Approved Code of Practice underpinning Regulation 7, with a public consultation planned later in the year, explicitly considering whether to introduce a statutory maximum working temperature for the first time. The trigger is straightforward: record UK heatwaves across 2025 and 2026 have pushed the "reasonable temperature" standard to breaking point in offices that were never designed for sustained extreme heat, and pressure has built from multiple directions for the law to catch up.

Trade unions including the TUC, Unite and UNISON have run active campaigns for a statutory cap, generally proposing a maximum of around 30°C for general work and 27°C for more physically strenuous roles. A parliamentary petition has separately called for a lower cap of 25°C. None of these figures are currently law — they represent campaign positions and consultation input, not the outcome of the review — but they indicate the range HSE's consultation is likely to engage with once it opens.

What this means for employers right now

Because the review is still at the consultation-planning stage, nothing about the legal position has changed yet. Employers should treat this as a live regulatory development to monitor, not a compliance deadline to prepare for immediately. That said, a few practical points are worth acting on regardless of how the review concludes:

• The "reasonable" standard is still enforceable today. A workplace that becomes genuinely hazardous — not just uncomfortable — during a heatwave can already trigger HSE interest under the general duty, even without a fixed number in law.
• Practical heat controls cost little and reduce exposure regardless of what the law eventually says. Flexible dress codes on hot days, portable fans or improved ventilation, relocating desks away from direct sun and glass frontage, and encouraging hydration breaks are all straightforward measures that don't depend on a specific legal trigger.
• Hybrid and flexible working policies can double as a heat-response tool. Some employers already use hot-weather flexibility — earlier start times, a temporary shift to home working on the worst days — as an informal safety valve; this connects naturally with existing hybrid working arrangements many organisations already have in place.
• Watch for the consultation once it opens. If HSE does introduce a statutory maximum, it will likely arrive with a defined implementation timeline similar to other recent regulatory changes, giving employers a window to adjust building management and policy documents rather than requiring immediate action on the day it's announced.

Why this gap has persisted so long

The absence of a maximum isn't an oversight so much as a reflection of how varied "too hot" can be across different types of work — a fixed number that makes sense for a call centre may be entirely wrong for a commercial kitchen or a warehouse with seasonal cooling constraints, which is part of why HSE's guidance has historically favoured a flexible "reasonable" standard over a single figure. The current review reflects a judgement that this flexibility has stopped working as UK summers become measurably hotter and more frequent, not that the original approach was poorly designed for the conditions it was written for.

Frequently asked questions

Is there currently a legal maximum temperature for UK workplaces?

No. The Workplace (Health, Safety and Welfare) Regulations 1992 require a "reasonable" temperature and set a commonly cited minimum guideline of 16°C, but there is no statutory maximum as of 2026.

What temperature are unions campaigning for as a legal maximum?

The TUC, Unite and UNISON have generally proposed around 30°C for general work and 27°C for more strenuous roles, while a parliamentary petition has called for a lower 25°C cap. None of these are currently law.

Can an employee legally refuse to work if their office gets too hot?

There is no specific temperature threshold that automatically entitles an employee to refuse work, but the general risk assessment duty still applies, and an employer that fails to act on a genuinely hazardous heat situation remains exposed under existing health and safety law.

Workplace temperature is a rare case of a health and safety topic where the practical risk (uncomfortable, sometimes hazardous heat) has outpaced the specific legal framework built to manage it — and HSE's 2026 review is a genuine, live attempt to close that gap rather than a settled change employers need to react to today. Learnsignal's CPD courses cover UK workplace health and safety compliance, including regulatory developments as they emerge.