When the Heat Becomes Unbearable: Workers Are Walking Out
As record-breaking temperatures sweep across the country, a growing number of workers are doing something that might surprise their managers — they are simply putting down their tools and going home. Factory floors are emptying. Offices are thinning out. Construction sites are grinding to a halt. Workers describe the experience of trying to function in extreme heat as being "like cats on a hot tin roof" — restless, uncomfortable, and unable to concentrate on anything beyond the sheer misery of the temperature around them.
It is a relatable image, but it also points to a serious and largely unresolved question in employment law: at what temperature is a workplace legally too hot to work in? The answer, perhaps shockingly, is that there is no defined legal maximum. In the United Kingdom, there is no statutory upper limit for workplace temperatures, leaving millions of workers in a legal grey area every time a heatwave strikes.
The Legal Landscape: What the Law Actually Says
Many people assume that employment law sets a clear ceiling on how hot a workplace can get before workers are entitled to leave or refuse to work. This is a common and understandable misconception. In reality, the Health and Safety at Work Act 1974 and the Workplace (Health, Safety and Welfare) Regulations 1992 require only that workplace temperatures be "reasonable." The guidance from the Health and Safety Executive (HSE) suggests a minimum temperature of 16°C for most workplaces (13°C for those doing physical labour), but it stops far short of specifying a maximum.
The HSE does acknowledge that working in high temperatures can be a health and safety risk, and it advises employers to carry out risk assessments when conditions become uncomfortable. But without a hard legal number at the top end of the scale, enforcement is inconsistent and workers are often left relying on the goodwill of their employers rather than the protection of the law.
Why Is There No Maximum Temperature Law?
The absence of a legal upper limit is not an oversight — it is a deliberate policy position, and one that has been debated for years. The argument from government and some employer groups is that conditions vary so widely across industries that a single number would be impractical. A comfortable temperature for an office worker might be quite different from what is acceptable for someone working in a bakery, a steel mill, or an outdoor construction site.
Trade unions have long pushed back against this reasoning. The Trades Union Congress (TUC) has repeatedly called for a maximum workplace temperature of 30°C (or 27°C for those doing strenuous work), above which employers would be required to take action. So far, those calls have not translated into legislation, despite growing public and parliamentary pressure.
The Real-World Impact on Workers
The consequences of this legal gap are felt most acutely by workers in physically demanding or poorly ventilated environments. Warehouse operatives, delivery drivers, care workers, kitchen staff, and those working outdoors face the greatest risks during a heatwave. Heat-related illness — ranging from mild heat exhaustion to life-threatening heatstroke — is a genuine occupational hazard, and one that is preventable.
Beyond the health risks, there is a significant productivity impact. Research consistently shows that cognitive performance declines as temperatures rise, with concentration, decision-making, and reaction times all suffering in the heat. Workers are not being dramatic when they say they cannot function properly — the science backs them up.
What Employers Are Legally Obliged to Do
Even without a defined maximum temperature, employers still have meaningful legal obligations when it comes to heat at work. Under general health and safety law, employers must:
- Carry out a risk assessment when temperatures in the workplace may pose a risk to workers' health, taking into account factors such as humidity, air movement, and the nature of the work being done.
- Introduce reasonable control measures to reduce heat risk. These can include providing fans or portable air conditioning units, allowing more frequent rest breaks, offering cold drinking water freely and without cost, and adjusting working hours so that the most physically demanding tasks are completed during the cooler parts of the day.
- Allow workers to dress more informally where appropriate, relaxing uniform or dress code requirements during periods of extreme heat.
- Monitor the health of workers who may be particularly vulnerable to heat, including older employees, pregnant workers, and those with certain medical conditions.
Employers who ignore these obligations risk not only the health of their staff but also legal liability. Workers who suffer a heat-related illness as a result of employer negligence may have grounds for a personal injury claim.
Your Rights as a Worker in a Heatwave
If you are struggling with extreme heat in your workplace, you do have options. Start by raising the issue formally with your line manager or employer, making it clear that the conditions are affecting your health and ability to work safely. If your employer fails to act, you can report the situation to the HSE, which has the power to investigate and, where necessary, serve improvement or prohibition notices.
If you are a trade union member, your union representative can be a valuable ally in pressing your employer to take action. Collective complaints tend to carry more weight than individual ones, and your union will be familiar with the relevant health and safety frameworks.
In extreme cases, Section 44 of the Employment Rights Act 1996 gives workers the right to leave or refuse to return to a workplace that they reasonably believe poses a serious and imminent danger to their health — and protects them from dismissal or detriment for doing so. Using this right can be a significant step, but it is a genuine legal protection that exists precisely for situations where an employer has failed in their duty of care.
The Case for a Maximum Temperature Law
As climate change makes extreme heat events more frequent, more intense, and longer-lasting, the argument for a legal maximum workplace temperature has never been stronger. What was once a seasonal inconvenience is increasingly becoming a serious public health and labour rights issue. Other European countries have introduced clearer protections, and the UK's continued resistance to setting a legal ceiling looks increasingly difficult to justify.
Workers should not have to choose between their health and their income. Until the law catches up with the climate reality, knowing your rights — and holding your employer to their existing obligations — is the most important tool you have.