Legal working temperatures

Legal Working temperatures


Ensuring the health and safety of your staff forms an important part of your duties as an employer, including the provision of a workplace that is neither too hot nor too cold.

In this guide, we examine the rules on minimum and maximum workplace temperatures, providing employers with practical advice on the provision of a safe, lawful and comfortable working environment.

What does the law say about workplace temperatures?

In the UK, there is no law specifying minimum or maximum working temperatures, or determining when it is legally deemed too hot or too cold to work. That said, under the provisions of the Workplace (Health, Safety and Welfare) Regulations 1992, the temperature in indoor workplaces during working hours must be “reasonable”. The 1992 regulations also require that:

  • any method of heating or cooling used by an employer does not result in the escape into the workplace of fumes, gas or vapour likely to cause injury or be offensive to anyone,
  • a sufficient number of thermometers are provided by the employer to enable staff at work to determine the workplace temperature.

Under the Approved Code of Practice from the Health and Safety Executive (HSE), employers are advised to maintain a minimum temperature of at least 16°C where the work activity is mainly sedentary, or 13°C if the work involves rigorous physical effort. However, these recommended temperatures are not an absolute legal requirement, where the employer will be left to decide what constitutes reasonable comfort in the context of their workplace.

For instance, it would be impractical to maintain the recommended temperatures in work areas which need to be open to the elements, or where food and other products need to be kept cold. In these cases, the temperature should be as close to the recommended levels as is practical.

The HSE does not provide a recommended maximum workplace temperature. This is because any meaningful figure cannot be set at the upper end of the scale due to the high temperatures found in, for example, foundries or glass works. Factors other than air temperature can also come into play in hot working environments, including radiant temperature, air velocity and humidity. That said, if the temperature at work is uncomfortably high because of hot processes, or even building design, the employer must still take all reasonable steps to ensure that workplace temperatures are at a comfortable level.

Employer duty of care for workplace temperature

Employers have a statutory duty under the Health and Safety at Work etc Act 1974 to ensure, so far as reasonably practicable, the health, safety and welfare of their employees at work. This means that all employers are required by law to protect their employees from harm, including harm caused by excessive or uncomfortable workplace temperatures.

The Management of Health and Safety at Work Regulations 1999 require employers to undertake a suitable and sufficient assessment of the risks to the health and safety of their staff, and take steps to control those risks where necessary. The employer must therefore consider the circumstances in which workplace temperatures might expose employees at work to any risk of illness or injury, and whether they’re doing enough to prevent that risk from arising. Under the 1999 regulations, an employer must:

  • identify the possibility of illness or injury from workplace temperatures
  • decide how likely it is that someone could be harmed in this way and how seriously
  • take action to eliminate the hazard, or if this isn’t possible, control the risk.

For most small, low-risk businesses exposed only to seasonal risks from hot or cold temperatures, the steps that need to be taken to control these risks are fairly straightforward. In most cases, this will be less about reducing the risk of illness or injury, and more about ensuring the thermal comfort of employees at work. Thermal comfort describes how acceptable a person considers their temperature, ie; whether they feel too hot or too cold.

For high-risk businesses, for example, those with extreme workplace temperatures arising from hot or cold processes, or buildings with high glass content, employers should consult with employees or their representatives to establish sensible means to cope. The employer should also secure expert legal advice on how to comply with the regulatory requirements where there’s any risk of illness or injury from excessive temperatures.

Managing risks of workplace temperatures

When managing and controlling the effects of workplace temperatures, much will depend on the normal operating temperature of the environment in question. However, in most indoor working environments, an employer should provide:

  • a reasonable working temperature in workspaces, usually at least 16°C, or 13°C for strenuous physical work, unless other laws require lower temperatures
  • local heating or cooling, making the best use of radiators, fans and opening windows where a comfortable temperature cannot be maintained throughout each workspace
  • heating or cooling systems that do not give off dangerous or offensive levels of fumes
  • thermal clothing and rest facilities, if necessary, for example, for hot work or cold stores
  • sufficient room in all working areas
  • sufficient breaks to enable employees to warm up or cool down, with the provision of additional facilities, such as a hot drinks machine or cold water dispenser
  • relaxing formal dress codes provided this doesn’t compromise the wearing of any personal protective equipment at work designed to protect employees from other risks
  • systems of work to limit an employee’s exposure to extreme high or low temperatures, such as flexible working, job rotation or work station rotation.

Where there are very high or low workplace temperatures created by the work, for example, from hot and cold processes, these temperatures can lead to serious health risks if not managed effectively. In these circumstances, employers should regularly review their working practices in the context of thermal conditions, where necessary implementing additional controls to manage specific risks such as cold stress, heat stress and dehydration. This could include medical screening or health surveillance for staff who have special requirements due to either pregnancy, hormonal imbalance, illness, disability or being on medication.

Specific consideration should also be given where personal protective equipment (PPE) must be worn in any workplace with extreme temperatures. PPE can significantly increase the risk of heat stress, contributing to the level of heat being generated inside the body and reducing the wearer’s ability to evaporate sweat. Further, the wearer may be unable to remove this clothing to enable them to cool down, as to do so would expose them to the primary hazard that the PPE is intended to protect them from.

Employers should regularly re-evaluate their PPE as there may be newer and lighter alternatives, providing improved levels of protection and comfort. They should also periodically revisit their risk assessment to consider if the process could be automated, or alternative systems of work or controls introduced.

Minimum & maximum workplace temperatures

The 1992 regulations provide that an employer must maintain a reasonable temperature in indoor environments during working hours. There is no statutory definition of what constitutes ‘reasonable’, although the HSE Code of Practice states that the temperature inside the workplace should provide “reasonable comfort without the need for special clothing”. Where this is impractical, for example, because of hot or cold processes, all reasonable steps should be taken to achieve a temperature that is as close as possible to being comfortable.

In the context of low temperatures, the guidance from HSE is clear. The temperature in workspaces should normally be at least 16°C, unless much of the work involves physical exertion, in which case the temperature should be at least 13°C. When it comes to high temperatures, there is no such clarity within the code, although employers are still duty-bound to prevent staff from being uncomfortably hot. The employer should also provide enough thermometers in suitable locations around the workplace so that employees can check the temperature.

Even where an employer has provided what would be regarded by most as an acceptable workplace temperature, thermal comfort is very subjective. This is because how someone responds to heat can depend on personal factors, including age, weight, fitness and clothing, as well as environmental factors, including the source of any heat and degree of humidity.

Issues of thermal discomfort, either hot or cold, can also arise from anyone whose work station is hit by direct sunlight, sited next to plant or pipes that radiate heat, or is exposed to a draught. In any one of these circumstances, the employer should still take all reasonable steps to maintain a comfortable temperature for that person, such as shading windows, insulating sources of radiant heat, providing air cooling plant or re-locating their work station.

Can employees refuse to work if the temperature is too high or too low?

The extent to which an employee can reasonably refuse to work if the temperature is either too high or too low will depend on the circumstances involved. These could include how extreme the temperatures have become, how long these temperatures have or are likely to persist, and what steps have been taken by the employer to reduce the employee’s discomfort.

In theory, an employee’s refusal to work could be classed as a misconduct matter, although responding with disciplinary action could, of itself, expose an employer to legal proceedings. Any disciplinary proceedings brought against an employee who has complained about a health and safety matter at work could be classed as an unlawful detriment, and any dismissal for refusing to work in unsafe working conditions could be deemed automatically unfair.

Equally, if an employee feels so physically uncomfortable that they’re threatening to ‘lay down tools’ as a result of excessive workplace temperatures, any steps taken by the employer to pressure them into working could result in their forced resignation and — given the subjective nature of thermal discomfort— a potentially viable basis for a claim for constructive dismissal.

What if the employer fails in their duty in relation to workplace temperature?

If an employer fails in their duty to provide a reasonable temperature at work, at the very least this is likely to give rise to staff complaints. However, in cases where excessive workplace temperatures result in illness or injury, this could result in a costly and time-consuming claim for breach of statutory duty. The employer can also be prosecuted for breach of health and safety law, not to mention various other serious and costly consequences for their business, including low performance and productivity, higher staff turnover and a damaged reputation.

Given the serious consequences of failing to comply with the law on workplace temperature, it’s vital that all employers undertake a thermal comfort risk assessment, even for seasonal risks, and take all reasonable steps to control any risks identified.

Workplace temperatures FAQs

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Legal disclaimer

The matters contained in this article are intended to be for general information purposes only. This article does not constitute legal advice, nor is it a complete or authoritative statement of the law, and should not be treated as such. Whilst every effort is made to ensure that the information is correct, no warranty, express or implied, is given as to its accuracy and no liability is accepted for any error or omission. Before acting on any of the information contained herein, expert legal advice should be sought.


Gill Laing is a qualified Legal Researcher & Analyst with niche specialisms in Law, Tax, Human Resources, Immigration & Employment Law.

Gill is a Multiple Business Owner and the Managing Director of Prof Services - a Marketing & Content Agency for the Professional Services Sector.

Legal disclaimer

The matters contained in this article are intended to be for general information purposes only. This article does not constitute legal advice, nor is it a complete or authoritative statement of the law, and should not be treated as such. Whilst every effort is made to ensure that the information is correct, no warranty, express or implied, is given as to its accuracy and no liability is accepted for any error or omission. Before acting on any of the information contained herein, expert legal advice should be sought.