Hot town, summer in the city

This July saw exceptional heat waves in Europe, with the UK clocking a new national record of 38.7C. This unusually early spell of heat was a result of Saharan hot air sweeping northwards as far as Scandinavia and the Arctic. While we have no certainty over what the rest of the summer might bring – the opening salvos in August have largely featured cooler weather and deluges of rain – when it does get hot, employers need to consider what impact this has on their employees.

Guidance on temperature in the workplace can be found on the Health and Safety Executive (HSE) website. While UK law does not specify a maximum temperature in the workplace (since some workplaces involve extreme temperatures regardless of the weather, such as certain manufacturing processes) employers do have a legal obligation to provide a ‘reasonable’ temperature in the workplace.

What is ‘reasonable’ will depend on the type of work being done (e.g. physical or sedentary) and the type of workplace (e.g. a factory, kitchen, office etc.). Employers should keep temperature at a comfortable level as well as provide clean and fresh air.

Maintaining what is called thermal comfort for employees is not simply a case of considering the air temperature. Thermal comfort depends on the following six basic environment and personal factors:  

  • Air temperature – the temperature of the surrounding air.
  • Radiant temperature – this may be generated by heat sources such as cookers, dryers, ovens etc.
  • Air velocity – this can help to cool employees either as the air is cooler or simply by convection.
  • Humidity – high humidity can reduce the ability to cool off by sweating, and can be a problem inside impermeable personal protective equipment (PPE).
  • Clothing insulation – again wearing PPE can significantly increase thermal discomfort.
  • Work rate/metabolic heat – the harder an individual is working physically the more heat they produce. An individual’s size, weight and age can also impact on thermal comfort.

The HSE provide a thermal comfort checklist which can be used as part of a wider risk assessment of the workplace or any given activity.

What should employers do?

Although the law does not specify a maximum temperature in the workplace, it is in the interests of both employers and employees to adopt a flexible approach during periods of hot weather. Employers are not required by law to provide air conditioning in the workplace. They are however required to provide suitable drinking water facilities for employees.

Practical steps which the HSE guidance suggests might be considered include:

  • Using or installing air conditioning systems.
  • Using blinds or curtains to block out the sun.
  • Allowing employees to take more frequent breaks.
  • Encouraging employees to drink more water.
  • Relaxing start / finish times to avoid rush hour travel.
  • Allowing employees to work from home if possible.

What about dress codes and uniform?

Employers are not obliged to relax any dress code or uniform requirements during hot weather. However, where appropriate, they may consider relaxing these to allow more casual, cooler clothes to be worn.

Work which requires Personal Protective Equipment (PPE) to be worn is a particular problem area. PPE can quickly lead to heat stress as it is often heavy and it can prevent efficient perspiration. In these situations, the HSE guidance suggests that employers may want to consider additional changes including permitting work to progress more slowly, rotating staff more frequently or allowing longer times between tasks in which PPE is worn.