Temperature in the workplace

What is thermal comfort?

Thermal comfort is based on one’s own perception, so one person’s thermal comfort can be another person’s thermal discomfort.

Factors affecting thermal comfort?

  • External environmental conditions
  • Ventilation and heat sources
  • How physically demanding the work is
  • Clothing
  • Personal preference

Workplace temperature

Regulation 7(1) of The Workplace (Health, Safety and Welfare) Regulations 1992 state that during working hours, the temperature in all workplaces inside buildings shall be reasonable.

The Approved Code of Practice L24 expands on the above and details that the “temperature of a workplace should normally be at least 16 degrees Celsius”. It goes on to say, “if work involves rigorous physical effort, the temperature should be at least 13 degrees Celsius”.

Keeping cool at work:

  • Switch on air conditioning or fans to keep workplaces comfortable.
  • Use blinds or curtains to block sunlight.
  • Staff working outside must wear appropriate clothes and use sunscreen to protect from sunburn.

Stay hydrated:

As an employer you must provide their staff with suitable drinking water in the workplace. You should advise your staff to drink plenty of water throughout the day to prevent dehydration.

Getting to work:

Please remember that public transport such as buses and trains can be affected by the hot weather. This could affect staff attendance and their ability to arrive at work on time. You should advise your staff to check timetables and services in advance and to speak to you if they become aware of any problems.

Vulnerable workers:

Some of your staff may be more adversely affected by the hot weather, for example, expectant mothers, the elderly or those on some medications. You may wish to more frequent rest breaks and providing fans or portable air-conditioning units if the existing ventilation is not adequate.


Although you are not under any obligation to relax your dress code or uniform requirements, during extreme hot weather it may be advisable to relax the rules for wearing ties or suits for example.

Reasonable adjustments that an employer can make during times of extreme heat:

  • You can introduce flexible working patterns, such as job rotation, moving workers to cooler parts of the building where possible.
  • You can allow enough breaks to allow workers to get cold drinks or cool down
  • You can relax formal dress codes – but make sure personal protective equipment is used if required

Personal protective equipment (PPE):

During times of extreme heat PPE can reduce the body’s ability to evaporate sweat and can lead to an increase in body heat.

You can encourage workers to remove PPE immediately after it is needed – This should prevent any heat retained in their clothing from continuing to heat them.

PPE may prevent workers removing clothing in case it exposes them to the hazard it is protecting them from. Where PPE is required, it could cause heat stress.  This can be due to its weight and the fact that it prevents sweat evaporating from the skin. In these situations, employers should make reasonable adjustments such as:

  • allow slower work rates
  • rotate staff out of this environment on a more frequent basis
  • allow longer recovery times
  • provide facilities for PPE to be dried so it can be worn again
  • consider scheduling work to cooler times of the day
  • review your risk assessment to see if automated or alternative systems of work can be introduced
  • re-evaluate your equipment as newer PPE may be lighter and provide improved levels of protection and operator comfort

It is important to make sure employees continue to wear PPE correctly despite workplace temperatures.

Further reading