The Legal Position

An employer must provide a working environment which is, as far as is reasonably practical, safe and without risks to health. In addition, employers have to assess risks and introduce any necessary prevention or control measures, and the risk from high (or low) temperatures, and of skin cancer due to exposure to the sun, should always be considered in any risk assessment,

Unfortunately there is no maximum temperature for workers although the Workplace (Health, Safety and Welfare) Regulations state the temperature inside workplace buildings must be ‘reasonable’. In addition, the approved code of practice to these regulations states that ‘all reasonable steps should be taken to achieve a comfortable temperature’.

The TUC has called for a maximum temperature of 30°C (27°C for those doing strenuous work), so that employers and workers know when action must be taken. However even if the temperature is slightly below that, employers should still attempt to reduce temperatures if they get above 24°C and workers feel uncomfortable

The Approved Code of Practice to the Workplace Regulations gives examples of what employers must do to ensure a reasonably comfortable temperature for indoor workers. This includes:

  • Insulating hot plants or pipes
  • Providing air cooling plants
  • Shading windows
  • Sighting workplaces away from places subject to radiant heat

Where this is not sufficient, it states that employers must install local cooling systems, increase ventilation, or fans. The code of practice also says that other factors, such as protective clothing, physical activity, radiant heat, humidity, air movement, and length of time of a person doing a job must all be taken into account when assessing what a ‘reasonable temperature’ is.

In addition, the Code of Practice requires employers to provide a suitable number of thermometers to enable workers to check temperatures in indoor workplaces.

The regulations require employers to provide ‘effective and suitable ventilation’, but safety representatives should ensure this is not achieved simply by opening doors, which may be acting as fire doors.

There is also guidance to the regulations that say that protection from the excessive effects of the sun in buildings can be achieved by introducing shading and using reflective materials. Some examples of the measures which can achieve this, either in isolation or in combination, are:

  • introducing awnings;
  • internal or external louvred blinds;
  • using dense vegetation, e.g. trees to provide shading;
  • use of anti-reflective glazing, e.g. by using films or upgrading glazing;
  • introducing overhangs or recesses to windows;
  • reducing unnecessary glazing on the sides of the building receiving the most sunshine;
  • improving the overall thermal mass of the building by using energy-efficient materials which allow heat to be stored and released at cooler times of the day.