Legal working temperature in the UK: a guide for employers

After the past three summers in the UK have been the warmest on record, the nationwide discourse surrounding acceptable working temperatures grows louder. According to recent reports, worker productivity drops by 2 – 3% for every degree above 20 degrees, and it doesn’t end there. 

Unmanaged workplace heat carries significant costs: higher employee turnover, increased rates of workplace accidents due to fatigue and lost concentration, and escalating rates of weather-related absenteeism.  

With rumours around maximum working temperatures and employer obligations, we’ve laid out the facts on legal working temperatures in the UK so that you can support your team, hot or cold. 

Are there legal maximum and minimum workplace temperatures? 

Legal minimum temperature 

While there is no absolute legal temperature that employers must keep their workplaces above, guidance in the Health and Safety Executive (HSE) states that indoor temperatures must be reasonable during working hours. The general rules are as follows: 

• For standard indoor workplaces, like offices and cafes, the temperature should remain at 16 degrees or above. 

• For larger indoor spaces like warehouses, where lots of physical work is involved, the temperature should remain at 13 degrees or above. 

Legal maximum temperature 

In UK law, there is currently no maximum legal temperature that employers must consider. However, the Workplace (Health, Safety and Welfare) Regulations 1992 state that indoor workplace temperatures must be kept to a reasonable standard. 

With extreme temperatures growing hotter by the year in the UK, trade unions continue to campaign for a legal maximum of 30 degrees for general workspaces and 27 degrees for physical labour but note that this is not currently law. 

Outdoor workers 

Outdoor workers are governed by the same regulations as indoor workers but because outdoor temperatures can’t be maintained or altered, the focus is on health and safety and risk mitigation. 

Employers have a legal duty of care to their outdoor employees and should conduct thorough risk assessments of all types of weather in order to provide the appropriate support to their employees. This can look like: 

• Thermal PPE 

• Heated break shelter and hot beverages 

• Shift or task rotation 

• Heat PPE and UV-blocking gear 

• Shaded break areas and drinking water 

• Adjusted scheduling of shifts or tasks to avoid peak sunlight 

Health and safety obligations 

With there being no laws in place regarding minimum and maximum temperatures in the workplace, employees may see this as there being nothing in place to hold employers accountable, but this is not true. Instead, the focus remains on health and safety obligations that employers must meet by law. 

Letting employees work in extreme heat can lead to:  

• Heat exhaustion and heatstroke that causes fainting, headaches, and dizziness 

• Dehydration and loss of concentration, leading to an increased chance of accidents 

• Heat rashes, sunburn, and physical muscle cramps as the body attempts to cool down 

Letting employees work in extreme cold can cause: 

• Hypothermia that induces symptoms like uncontrollable shivering, confusion, and physical fatigue 

• Numbness in fingers that reduces grip strength and precision, heightening the risk of accidents, particularly in manual labour. 

• Respiratory problems like worsened asthma 

• Slips and falls from icy walkways and stairs 

Employees who suffer physical injuries or serious medical conditions due to the heat or cold making their workplace unsafe can sue for negligence.  

Employees who may need additional support 

Consider also, there may be employees in your team that need additional support with extreme weather. Workers who are pregnant, disabled, older, or working outdoors are likely to be more easily affected by the temperature, so making additional adjustments for these staff members is strongly recommended. 

Can employees refuse to work if it’s too hot? 

An employee cannot refuse to work if the temperature rises beyond a specific number. Remember that there is currently no legal working temperature in the UK. 

That being said, employees who leave work due to a reasonable believe that there is serious and imminent danger are protected by Section 44 of the Employment Rights Act 1996. Withholding pay or penalising them for this behaviour can lead to employment tribunals where the employer will be unlikely to succeed. 

Employer responsibilities 

There are multiple ways that employers can maintain a reasonable and comfortable indoor temperature for workers. 

Responsibilities during hot weather 

First, it’s important to conduct a thorough risk assessment when conditions are predicted to, or become, uncomfortably hot. This will support you in making informed decisions going forward. 

To support your employees throughout hot weather, provide constant access to fresh drinking water and well-ventilated spaces through the use of water fountains, fans, or air-conditioning units. 

Responsibilities during cold weather 

Again, always conduct a risk assessment prior to making adjustments to your workplace as this ensures no crucial gaps are left. 

 To help your employees feel comfortable and stay focused despite extreme cold, ensure central heating is effective and can maintain a minimum of 16 degrees. Provide temporary heaters if your main heating is ineffective and make sure that outdoor walkways are gritted and slip-proof.  

Even small touches like having the means to make hot drinks in break areas go a long way and show your employees that you’re thinking about their well-being. 

Practical tips for employers 

Making reasonable adjustments doesn’t mean implementing huge changes to your commercial space. Often, an accumulation of simple policy changes can do most of the work: 

1. Allow employees flexibility with the beginning and end of their shifts to avoid travel in boiling or freezing conditions. 
2. Relax any dress codes that require formal business wear in favour of breathable, loose clothing. For uniformed work, ensure you have a range of options available so that workers can warm up with fleeces or jackets while still looking part of the workforce. 
3. Adapt work patterns to allow for more frequent breaks, introduce task rotation, and move physically demanding tasks to early or late times in the day. 
4. Support staff members requests to work from home if office temperatures are uncontrollable or bordering on becoming dangerous. 

Common myths about workplace temperatures  

Widespread confusion around UK temperature regulations have circulated in recent years. Here are the answers to a few key statements that we see most commonly: 

“It’s illegal to work in an environment that exceeds 30 degrees.” 

This is not true. As previously mentioned, there is no legal maximum working temperature in the UK. 

“The 16-degree minimum rule is a strict and legal requirement.” 

While this temperature is a strongly recommended benchmark figure from HSE, it is not a statutory cutoff.  

Be aware that if an employee were to suffer a medical condition due to their place of work being too cold, the business will be liable. 

“Remote workers’ room temperatures are not the employer’s responsibility.” 

This is not true. Despite the fact that the worker is in their own home, the employer should still offer guidance on maintaining safe working conditions. 

How Sapphire HR can help 

Managing workplace temperatures goes beyond staff comfort. As the general opinion of the working population shifts in the face of more frequent extreme weather, employer responsibilities are pushed further into the limelight.

The Sapphire HR team support businesses in completing risk assessments and ensures working condition policies meet current UK HSE standards. Instead of reacting when things go wrong, get ahead before winter arrives and make sure you’ve got a workplace that isn’t only comfortable for your employees, but safe and suitable too. Get in touch today for tailored guidance.