Working in the office during a heatwave - is it too hot to work in the office?
Whilst there are assumptions, there is no set maximum legal temperature for workplaces under UK law. However, employers are required to ensure that workplace temperatures remain “reasonable” and that staff can work safely and comfortably. Nevertheless, the challenge is determining what “reasonable” actually means in practice.
What does the UK Law say about workplace temperatures?
The primary legislation governing workplace temperatures is the Workplace (Health, Safety and Welfare) Regulations 1992. These regulations impose legal duties on employers to ensure that most indoor and outdoor workplaces meet basic standards for health, safety and welfare. These regulations also state that temperatures in indoor workplaces must be “reasonable” during working hours.
The Health and Safety Executive (HSE) recommends that indoor workplace temperatures should normally be at least:
16°C for sedentary work such as office environments, or
13°C, where work involves significant physical effort.
Importantly, their figures are guidance rather than strict limits.
Is there a maximum legal working temperature?
No, UK Law does not impose a strict minimum or maximum working temperature.
The HSE has stated that it would be difficult to impose universal limits because workplaces vary significantly. For example, temperatures considered acceptable in an office would differ greatly from those in foundries, bakeries, warehouses or commercial kitchens.
Nonetheless, employers still have a legal duty under the Health and Safety etc. Act 1974 to protect employee health, safety and welfare. Heat is recognised as a workplace hazard, meaning employers must assess and manage risks associated with excessive temperatures.
Employer responsibilities during hot weather
When temperatures rise, employers should take reasonable steps to maintain a safe and comfortable environment. Depending on the workplace, this may include:
Providing fans or air conditioning;
Allowing more frequent breaks;
Relaxing workplace dress codes (such as the removal of ties or blazers in the office);
Providing access to cold drinking water;
Adjusting working hours;
Improving ventilation; or
Allowing remote or hybrid working where possible.
The HSE also advises employers to carry out temperature-related risk assessments and consult staff about practical solutions.
For outdoor workers, additional protections may be necessary, including shaded rest areas, sun protection and revised shift patterns during extreme heat.
While employers are legally required to take reasonable steps to keep staff safe and comfortable during periods of extreme heat, unfortunately for employees, there is no statutory obligation to provide ice creams or pina coladas – although doing so may prove far more popular than another “please stay hydrated” email from HR, who may still prefer water coolers over cocktail umbrellas!
Thermal Comfort: More than just a thermometer reading
One common misconception is that workplace safety is determined solely by air temperature. In reality, the HSE uses the concept of “thermal comfort”, which considers a range of factors, such as:
Humidity;
Air movement;
Type of work being carried out;
Clothing or Personal Protective Equipment (PPE) requirements;
Radiant heat sources; and
Individual health conditions.
A workplace may therefore feel uncomfortably hot or cold even if the temperature appears acceptable on paper.
Can employees refuse to work if it’s too hot or too cold?
Employees may have protections under Section 44 of the Employment Rights Act 1996 if they reasonably believe they are in “serious and imminent danger” and they should not be subject to a detriment because of this. This can include extreme workplace temperatures where employers have failed to act appropriately.
That said, there is no automatic right to walk out simply because the office feels uncomfortable. Employees are generally expected to raise concerns internally first, allowing employers an opportunity to address this issue.
In answer to this question, potentially, but only in limited circumstances.
Special consideration for vulnerable employees
Employers should be mindful that some workers may be more vulnerable to temperature extremes, including:
Pregnant workers;
Older workers;
Workers with medical conditions, and/or
Workers who are required to wear heavy PPE
Under the Equality Act 2010, employers may need to make reasonable adjustments where high or low temperatures place certain workers at a disadvantage.
Practical advice for employers
With extreme weather events becoming more common in the UK, proactive temperature management is no longer simply good practice. It is increasingly becoming a legal and employee relations issue.
Employers should consider:
Reviewing temperature risk assessments regularly;
Updating heatwave and cold weather policies;
Training managers on thermal comfort obligations;
Encouraging staff to report concerns early, and/or
Maintaining clear communication during extreme weather events.
A failure to manage workplace temperatures appropriately can lead not only to reduced productivity and morale, but also to potential grievances, sickness absence, and health and safety claims.
How can Orwins help?
Workplace temperature obligations are rarely straightforward, and the pressure on employers during extreme weather can be significant.
The employment law team at Orwins advises businesses on everything from workplace policies and risk assessments to employee relations and practical compliance strategies. Our focus is on helping you meet your legal obligations with clarity and confidence.
Whether you need to review a heatwave procedure, update your staff handbook with temperature guidelines, or respond to a workplace complaint, we'll give you commercially focused advice that works for your business.
