Created on: 14 Jul 2023

Some workers face extremes of temperature, eg outdoor workers, workers in the food industry who work in cold stores and bakery or foundry workers, but for all workers the wrong temperature causes problems.

People will complain of discomfort if the heating cannot cope in cold weather or if ventilation is bad when it is hot. Cold snaps, heatwaves and breakdowns pose additional problems.

Working in the wrong temperature can mean loss of concentration, irritability, tiredness, discomfort and increased accident risks. Too much heat can cause fatigue, extra strain on the heart and lungs, dizziness and fainting, or heat cramps due to loss of water and salt.

Hot, dry air can increase the risk of eye and throat infections. In extreme circumstances there heat stroke can occur. Tiredness and loss of concentration can also lead to increased accident risks. As a last resort, in unavoidably hot or cold work areas, employers should provide suitable protective clothing and rest facilities, and limit the amount of time that individuals work in these areas.

Regulation 7 of the Workplace Regs states that the ‘temperature in all workplaces inside buildings shall be reasonable during working hours.’ A ‘reasonable temperature’ is defined in the accompanying ACoP as that which provides reasonable comfort without special clothing and should normally be at least 16oC or at least 13oC where much of the work involves physical effort (such as repeated exertion to the extent that a temperature of 16o would be uncomfortably warm).

The ACoP stipulates that where maintaining these standards are impractical then employers must take all reasonable steps to achieve a comfortable temperature as close to them as possible.

Regulation 7 also states that methods of heating or cooling must not produce harmful or offensive fumes, gases or vapours, and a sufficient number of thermometers must be provided to enable workers to check temperatures in indoor workplaces. The ACoP says thermometers need not be provided in each workroom but if the temperature in a particular workroom is uncomfortable the temperature in that room should be measured.

Too cold: Too much cold can mean chilblains, Reynaud's disease or white finger and frostbite. Cold conditions can also lead to fatigue since the body uses energy to keep warm.

There is an increased accident risk from numb fingers, obstruction by some kinds of protective clothing, slipping on ice, etc. Extreme cold for long periods can lead to hypothermia, loss of consciousness and eventual coma.

The acceptable zone of thermal comfort for most kinds of work lies between 16oC (60.8oC) - 24oC (55.4oC).

The acceptable temperatures for heavier types of work are concentrated in the lower parts of this range, while sedentary tasks may still be performed with reasonable comfort towards the opposite extreme.

The School Premises (General Requirements and Standards)(Scotland) Regulations 1967 includes the following provisions for minimum temperatures in different areas within schools:

Type of Accommodation


Number of air changes per hour to be heated by the heating system




Medical inspection room, changing room, bathroom, water closet and shower room


18.5oC (65oF)

Teaching space, dining room, nursery room, common room and staff room


17oC (62oF)

Assembly area, lecture hall, theatre and cinema


15½oC (60oF)



14½oC (58oF)

Cloakroom and corridors


13oC (55oF)



13oC (55oF)

Games hall


10oC (50oF)

When checking on compliance with these standards, care should also be taken to examine heating systems that are in use. These can cause problems of their own such as fumes, uneven temperature and draughts, dry air or too much humidity, insufficient fresh air, electrical hazards or fire hazards.

The above standards are guidelines but are not enforced by the Health and Safety Executive.

Enforcement action would not be taken unless the temperature was less than 16oC in classrooms, lecture theatres or other general work areas. If the temperature does not reach the minimum standards in any area where a teacher or a lecturer is required to work this matter should be raised with the head teacher or line manager.

There are many local agreements on the actions to take if the temperature does not meet the statutory maximum, advice on this should be sought from the Local Association or Branch.

Too hot: The law does not include specific standards for maximum temperatures, so reliance has to be placed on the general duties in Section 2 of HASAWA and the Workplace Regs (Reg 7 states that employers must ensure that during working hours, the temperature in all workplaces, inside buildings is ‘reasonable’).

The TUC is campaigning for a maximum workplace temperature of 30oC, or 27oC for those doing strenuous work.

Local agreements have been reached by some Local Associations on maximum temperatures to be allowed in schools. Such agreements specify the temperature at which measures should be taken to reduce the heat in the classroom or, in some circumstances, find alternative accommodation.

The ACoP says that "all reasonable steps should be taken to achieve a comfortable temperature", for example:

  • insulating hot pipes and equipment;
  • providing air cooling plants;
  • shading windows;
  • siting workstations away from hot areas; and
  • using fans and increased ventilation in hot weather.

Checklist: Temperature and Ventilation Possible Action

  1. One way of identifying a problem is by talking to your members or doing a survey. This may also build their support for solving the problem. You could ask them:
    • do they find it too hot or too cold at work?
    • does this happen at a particular time of year?
    • do they notice any draughts at work?
    • are there any problems with heating/cooling systems?
  2. Make an inspection of temperatures and heating and cooling systems. Most workplaces tend to be too cold for comfortable working, particularly in winter. What is the average temperature in your workplace and is there a thermometer available to measure it?
  3. Is the atmosphere hazy, oily, fume or dust-laden? If so:
    • are there sufficient air movements by general ventilation (windows, doors, vents)?
    • is any provision made for mechanical ventilation by fans, exhaust ventilation or other cleaning equipment?
    • are there maintenance and cleaning programmes for ventilation equipment?
  4. Draw up a list of the main problems with heating and ventilation, hot work and cold work.
  5. Prepare a report for management. Set out your aims and a plan of action on temperature and ventilation problems.