Can you leave work if it gets too hot? UK workplace temperature rules explained 

After several unusually hot spells across the UK this summer, offices, warehouses, kitchens and outdoor work sites have been feeling the heat. But is there a temperature at which employees can legally stop working and go home? 

The answer is less straightforward than many people expect. UK law does not set a maximum workplace temperature, so reaching 30°C or even 35°C does not automatically bring a working day to an end. 

There is no legal maximum temperature 

There is no single temperature that can be applied to every workplace. An office, bakery, warehouse and construction site create very different conditions, even when the thermometer shows the same number. 

Temperature is also only part of the picture. Humidity, ventilation, physical activity, direct sunlight and protective clothing can all affect how safely a person can work. 

However, the absence of a fixed limit does not allow employers to ignore extreme heat. The Health and Safety Executive treats heat as a workplace hazard. Employers must assess the risks, keep conditions reasonable and introduce suitable measures to protect workers. 

What should employers do during hot weather? 

Simple changes can make a significant difference. Employers may use fans or air conditioning, close blinds, improve ventilation and move workstations away from direct sunlight. 

They can also adjust working hours, reduce physically demanding tasks during the hottest part of the day and provide more frequent breaks in cooler areas. Suitable drinking water must be available in the workplace. 

Where it is safe to do so, employers may temporarily relax dress codes. Protective equipment should not simply be removed, as this could expose workers to a different danger. 

Outdoor workers may need shade, additional breaks, suitable clothing and heavier tasks moved to cooler hours. Employers should also consider whether workers are spending long periods in vehicles, enclosed spaces or direct sunlight. 

How can you recognise heat stress? 

Working in high temperatures can become more than an uncomfortable afternoon. Early signs of heat stress may include poor concentration, muscle cramps, dizziness, nausea, headaches, severe thirst and unusual tiredness. 

Fainting, confusion, hot dry skin, convulsions or loss of consciousness can indicate heat stroke, which is a medical emergency. 

Some workers may be more vulnerable, including pregnant employees and people with certain health conditions or disabilities. Employers should consider individual circumstances and make reasonable adjustments where necessary. 

Can you simply leave the workplace? 

A high temperature alone does not create an automatic right to walk out. Employees should first raise the issue with their manager, HR department or health and safety representative. They should explain how the conditions are affecting them and ask what action will be taken. 

Employment law can protect workers who leave or refuse to return to a workplace when they reasonably believe there is a serious and imminent danger that they cannot safely avoid. This is a high legal threshold and depends on the circumstances, so it should not be treated as a general rule allowing anyone to leave when they feel too warm. 

If concerns are repeatedly ignored, it is sensible to keep a record of temperatures, symptoms, messages and conversations with the employer. 

Could the law change? 

The Trades Union Congress has called for a legal maximum indoor temperature of 30°C, or 27°C for strenuous work. It also wants employers to take cooling measures when temperatures rise above 24°C and workers feel uncomfortable. 

These figures are proposals, not current legal limits. For now, the key question is not whether the thermometer has crossed one fixed line, but whether the employer is managing the risk properly.