There is no legal temperature at which you must stay home
As Britain faces temperatures approaching 40 degrees Celsius, its citizens are confronting a quiet legal paradox: neither workers nor parents possess a clear statutory right to stay home, yet the structures meant to protect them were never designed for this kind of heat. The law speaks in the language of comfort rather than thresholds, leaving individuals to navigate extreme conditions through guidance, goodwill, and improvisation. This moment is less a crisis of policy than a reckoning with infrastructure — a society discovering, in real time, that its buildings and its rules belong to a cooler world that may no longer exist.
- Temperatures nearing 40C are pressing workers and parents to ask whether they are legally entitled to stay home — and the answer, largely, is no.
- The absence of a legal heat threshold creates a vacuum of authority, forcing employers, head teachers, and individuals to make consequential decisions without clear guidance.
- Schools are bending rather than breaking — relaxing uniforms, shifting lesson locations, and adjusting timetables — while stopping short of the closures that would trigger formal accountability.
- Workplaces are similarly improvising, with Acas urging employers to treat closure as a last resort and to exhaust every adaptation — fans, dress code changes, flexible commutes — before sending workers home.
- Teaching unions are using the crisis to press a longer argument: that ad-hoc heat management is not a strategy, and that government investment in climate-resilient buildings is now overdue.
- Britain is muddling through this heatwave, but the structural gap between its built environment and its changing climate is becoming impossible to ignore.
Britain is bracing for temperatures that could reach 40 degrees Celsius, and the question running through offices and schoolyards is the same: do you have to show up? The answer is mostly yes — but with caveats.
There is no legal temperature threshold in the UK that permits refusing work or keeping a child home from school. The law requires workplaces to maintain 'comfortable' conditions and provide clean air, but offers guidance rather than hard limits. Notably, cold weather carries a minimum indoor temperature of 16 degrees Celsius — no equivalent ceiling exists for heat, leaving workers and parents in an uncomfortable position when temperatures climb.
Schools have no legal maximum classroom temperature, but they are not without options. Teaching unions recommend indoor spaces stay below 26 degrees, and head teachers are watching closely for signs of distress. Most schools will adapt rather than close — relaxing uniforms, moving lessons to cooler areas, adjusting start times, and scaling back physical activity. Parents are advised to send children in light clothing and hats with sunscreen applied. The government's position remains firm: children learn best in classrooms.
For workers, the picture is similarly constrained. Acas describes closure as 'a last resort in extreme circumstances,' urging employers to first exhaust alternatives — relaxed dress codes, cold drink breaks, fans, and flexible commuting arrangements. Outdoor workers receive more specific protections, including rescheduled tasks, shaded rest areas, and access to cool water. Drivers without air conditioning are advised to postpone non-essential journeys.
Behind all this guidance lies a structural problem that unions are now naming directly: schools and workplaces were not built for this. Teaching unions have called on the government to invest in climate-resilient buildings, arguing that relaxed uniforms and moved lessons are adaptations, not solutions. As extreme heat becomes more frequent, the gap between what existing infrastructure can tolerate and what the climate will demand is only growing wider.
Britain is bracing for temperatures that could reach 40 degrees Celsius by midweek, and the question rippling through offices and schoolyards is the same: do you have to show up? The answer, frustratingly, is mostly yes—but with important caveats that depend on where you work and who you are.
There is no legal temperature threshold in the UK that permits you to refuse work or keep your child home from school. The government does not advise schools to close during heat events, and employers are not required to shut down simply because the thermometer has climbed. What the law does require is something vaguer: that workplaces maintain "comfortable" conditions and provide "clean and fresh air." The Health and Safety Executive offers guidance rather than hard limits. For comparison, in cold weather, indoor workplaces must reach at least 16 degrees Celsius—or 13 degrees if the work is physically demanding. No such floor exists for heat. This asymmetry leaves workers and parents in an uncomfortable position when temperatures soar.
Schools have no legal maximum temperature for classrooms, but they are not powerless. Teaching unions have recommended that indoor spaces stay below 26 degrees Celsius, and school leaders will monitor conditions closely, watching for signs that children are tiring more quickly or showing signs of distress. If a head teacher decides closure is necessary, they must first consult the chair of governors and their academy trust. Most schools, however, will adapt rather than close. Uniform rules are being relaxed in many places, allowing children to wear PE kits instead. Lessons can be moved to cooler areas of the building. Start and finish times can shift to avoid the worst heat. Physical education may become less vigorous. Windows may be closed later in the day if outside temperatures exceed inside ones, though fans should not be used above 35 degrees. Parents are advised to send their children in light, loose-fitting clothing and wide-brimmed hats, with high-factor sunscreen. The government's position is clear: school attendance matters, and children learn best in classrooms, not at home.
For workers, the picture is similarly constrained. Acas, the workplace advice group, notes that except in extreme circumstances, workers are expected to follow their contracts and work with employers to find safe arrangements. Closure or inability to work due to heat should be "a last resort in extreme circumstances," according to Acas chief executive Niall Mackenzie, and any such decision should be made only when no alternatives exist and communicated well in advance. Employers can ease the burden by relaxing dress codes, providing frequent breaks for cold drinks, installing fans or air conditioning, and opening windows to circulate air. Those working from home should close curtains during the day and open windows on opposite sides of the house in morning and evening to create cross-ventilation.
Outdoor workers face particular challenges. The HSE recommends rescheduling work to cooler parts of the day, increasing rest breaks, providing shading in rest areas, and offering free access to cool water. Workers should be allowed to remove personal protective equipment while resting. Acas advises appropriate clothing and sunscreen. Public transport may be disrupted, and employers are urged to be flexible about arrival times and to allow staff to adjust their commutes. The RAC has suggested that drivers without effective air conditioning should "strongly consider" postponing non-essential journeys until the warning is lifted.
Behind all this guidance lies a structural problem that unions are now naming directly: schools and workplaces were not built for this. Teaching unions have called on the government to invest in making school buildings more resilient to extreme weather. Ad-hoc measures—relaxed uniforms, moved lessons, sedentary PE—can help, but they are not solutions. As heat events become more frequent, the gap between what existing buildings can tolerate and what the climate will demand will only widen. For now, Britain will muddle through with creativity and flexibility. But the question of whether that is enough is no longer theoretical.
Citações Notáveis
Except in extreme circumstances, workers usually need to follow their contracts and work with their employer to find a suitable and safe way to work— Acas chief executive Niall Mackenzie
School attendance is the best way for pupils to learn and reach their potential— UK government position
A Conversa do Hearth Outra perspectiva sobre a história
So there's genuinely no legal temperature at which you can just stay home from work or school?
That's right. The UK has set a minimum for cold—16 degrees in most workplaces—but no maximum for heat. It's a gap that becomes obvious only when temperatures spike.
Why would they set a floor but not a ceiling?
Cold was the historical concern. Heat waves are becoming the new normal, but the law hasn't caught up. There's also the assumption that people can adapt—remove layers, drink water, find shade. Cold is less forgiving.
But schools can't really adapt the same way adults can. What happens to a classroom at 40 degrees?
They'll move lessons to cooler parts of the building, relax uniforms, maybe shift the school day. But yes, there's a limit to what a brick building from the 1970s can do. That's why unions are pushing for actual investment in climate-resilient buildings, not just temporary fixes.
And employers—are they actually required to do anything?
They have to maintain "comfortable" conditions and provide fresh air. But "comfortable" is not defined. It's vague enough that it becomes a negotiation between employer and worker, not a clear legal line.
So the real answer is: it depends on how much your employer cares?
Essentially, yes. Though Acas does say employers should be flexible and creative. The guidance is there. Whether it's followed is another matter.