This information relates to minimum and maximum workplace temperatures and heating and ventilation issues.

Legislation and the working environment

The Workplace (Health, Safety and Welfare) Regulations 1992 and The Workplace (Health, Safety and Welfare) Regulations (Northern Ireland) 1993 apply to all workplaces, including schools and colleges, and stipulate that temperatures during working hours shall be ‘reasonable’.

Recommended temperatures


The temperature of a room should be appropriate to its normal use during any period it is occupied. The regulations state 16ºC should be the minimum, with 13ºC in areas where the occupants are lightly clad and where activity is vigorous (e.g. gymnasia).

Northern Ireland

For educational establishments, the Department of Education’s School Building Handbooks (Nursery, Primary and Secondary) states that a heating system should be capable of maintaining temperatures appropriate to a room’s normal use and, specifically, when the outside temperature is 0ºC:

  • 20ºC in areas where occupants are lightly clad and inactive (e.g. medical inspection rooms);
  • 18ºC where there is an average level of clothing and activity (e.g. classrooms and multi-purpose halls) but with the ability to adjust this simply to 15ºC depending on activity;
  • 15ºC in areas where the occupants are lightly clad and where activity is vigorous (e.g. gymnasia) and circulation areas.

The School Premises (General Requirements and Standards) (Scotland) Regulations 1967 stipulate the following minimum temperatures:

Medical room; changing room; bathroom; WC; shower room


Teaching space; dining room; nursery room; common/staff room


Assembly room; lecture hall; theatre and cinema




Cloakroom and corridors




Games hall



The Education (School Premises) Regulations 1999 stipulate the following temperatures:



Areas where there is a lower than normal level of physical activity because of sickness or physical disability including sick rooms and isolation rooms but not other sleeping accommodation


Areas where there is the normal level of physical activity associated with teaching, private study or examinations


Areas where there is a higher than normal level of physical activity (for example arising out of physical education) and wash-rooms, sleeping accommodation and circulation spaces.


All schools should consider the needs of pupils and staff with limited mobility and who may not generate as much body heat as a fully mobile person and may therefore need higher room temperatures.

At the same time, pupils who are hyperactive may need relatively cool environments.

These are issues which should be considered during the maintenance or installation of heating and ventilation systems.

Schools should also explore ways of managing room temperatures by the use of, for example, fans, blinds and additional heating/cooling equipment.

Recommended summer temperatures

While there are no statutory upper limits on working temperatures, the World Health Organization recommends 24ºC as a maximum temperature for comfortable working.

Research has shown pupils ability to learn is significantly impacted upon by high temperatures, with almost a 20% drop in results at 27ºC compared to 22ºC.

Peak air temperatures should not exceed 28ºC during normal working hours.

Excessive working temperatures

The Health and Safety Executive (HSE) and the Health and Safety Executive Northern Ireland (HSENI) affirm that employers are required by the Health and Safety at Work Act 1974 and the Health and Safety at Work (Northern Ireland) Order 1978 respectively to ensure, so far as is reasonably practicable, the health, safety and welfare of their employees. This, taken together with the provisions set out above under ‘Legislation and the working environment’, with the requirement for employers to make a suitable assessment of the risks to the health and safety of their workers and to take any necessary, reasonably practicable action to mitigate those risks, means that it is unacceptable for schools to require teachers to work in unreasonably high or low temperatures.

A sufficient number of thermometers must be provided so that temperatures may be checked and a record kept. Should an unacceptable rise or fall in temperature occur, then the employer should, in consultation with the NASUWT Representative, put in place appropriate emergency measures, which could be:

  • the provision of temporary (and safe) heaters which do not introduce fumes into the workplace;
  • the provision of suitable alternative room(s); and
  • closure or partial closure of the building.

If the employer is unwilling or unable to provide a solution which would be considered reasonable in the particular circumstances, advice from the NASUWT should be sought.


The importance of adequate ventilation

A supply of fresh air in classrooms is essential. Working in a high temperature can lead to loss of concentration, irritability, headaches, tiredness and discomfort. It can make people more vulnerable to accidents and affect the quality of their work. All practical measures must be taken to protect against fumes, dust and other impurities.

Ventilation within hygiene areas is particularly important as these are areas which often have problems of poor air quality.

The Regulations state that workplaces should be sufficiently well ventilated so that stale, hot or humid air is replaced at a reasonable rate, whilst not causing a draught.

The fresh-air supply rate should not fall below five to eight litres per second per occupant.

If an area, e.g. washrooms, changing rooms or cloakrooms, cannot provide adequate cross- ventilation (i.e. six changes of air per hour) by natural means, then it should be mechanically ventilated.

In Northern Ireland, all classrooms, working areas, halls, sick rooms and dormitories should be capable of being ventilated at a minimum of eight litres of fresh air per hour for each person normally occupying these areas to maintain comfortable conditions.

Excessive temperatures should be reported to the NASUWT Representative who should record daily temperature readings and make representations to the employer where necessary.

In deciding what is a reasonable workplace temperature, employers need to consider a wide range of factors including:

  • ventilation;
  • humidity;
  • the work involved;
  • the person undertaking the work;
  • what they are wearing (such as personal protective equipment); and
  • air movement.