Temperature and thermal comfort

Thermal comfort can be affected by many things including:

  • external environmental conditions
  • ventilation and sources of heat
  • how physically demanding the work is
  • clothing
  • personal preferences

Thermal discomfort (being too hot or too cold) is based on an individual’s perception, so thermal comfort for one person may be discomfort for another. For this reason the University cannot provide a thermal environment that suits everyone all the time, but aims to provide a thermal environment that satisfies the majority of people most of the time.


In the majority of cases working in environments that people find too hot or too cold will not lead to physical harm. However it will lead to complaints, affect morale and may affect productivity. It can contribute to stress and an increase in accidents, which could be a significant issue in high risk work environments.

Some work environments may be excessively hot, leading to a risk of heat stress, or excessively cold, leading to a risk of cold stress. Employees working outdoors during very hot weather may also be at risk from the effects of the sun (sun stroke, sun burn or skin cancer).

Work environments

Improving indoor thermal comfort

The University endeavours to provide appropriate room temperatures during the winter heating period (1 October - 30 April), (minimum 18oC for office space and 20oC for residential accommodation) but cannot control space temperatures during the summer period. In some instances it can be difficult to attain a reasonable temperature because external conditions are high and the nature of some of the University's buildings (particularly those built in the 1960s, with highly glazed concrete structures with flat roofs).

Physical controls

  • Insulate or clad heat sources.
  • Screen windows with reflective film, blinds or insulate with curtains.
  • Open windows (where allowable) and provide fans to increase air movement.
  • Insulate to reduce draught.

Where possible, position computer workstations out of direct sunlight (in the cooler part of the office), with the screen/keyboard at right angles to the window to reduce risk of glare or reflection (see advice on DSE AssessmentDSE AssessmentDSE Assessment).

Management controls

  • Separate the worker from the heat or cold source, for example by using barriers or restricting access.
  • Relax dress codes.
  • Prevent dehydration by ensuring cool water is available.
  • Rotate staff working in the environment to reduce exposure times.
  • Build in work or other breaks which would allow staff to rest in a comfortable environment.
  • Make sure employees can access windows safely to open them.
  • Allow flexible working times or home working where possible.
  • Review your risk assessment relating to the use of personal protective equipment (PPE).

PPE is intended to protect staff from a primary hazard, but sometimes people wear more than is necessary. Consider whether staff can wear less PPE and still have the protection they require or whether other controls would reduce or eliminate the need for PPE. Remember PPE should be a last resort.

Personal controls

Too hot

  • Dress appropriately for the conditions likely to be encountered. Use layers, so that you can adjust clothing if it becomes warmer or cooler.
  • Open windows (if you can do so safely), but do consider the effects of draughts on others.
  • Use window blinds provided to reduce draughts and solar gain.
  • Set fans and heaters on a moderate setting. Turning them on maximum doesn't make them any more effective.
  • Positioning fans at a low level (if you can do so safely) so that it cools your feet can also help.
  • If you work in an air conditioned environment, don't open windows or leave doors open, as it will reduce its effectiveness.

Too cold

  • Check windows are closed fully.
  • Check radiators are clear of items to ensure air flow.
  • Don't bring in heaters or fans from home to use.

The University does not support the acquisition or use of supplementary heaters. Such items can only be provided by the Estate Management Section in the event of temperatures falling below 18oC (eg due to an emergency or mechanical failure of the heating system) or at the discretion of the Director of Estate Management. For further information refer to the University's Energy PolicyEnergy PolicyEnergy Policy).

Dealing with thermal comfort problems


If the advice above is insufficient to resolve the problem, speak to your line manager. If you experience ill health related to the thermal conditions a health and safety incident form should also be completed.


  1. Request a thermometer (available from the Estates Management Helpdesk Estates Management Helpdesk Estates Management Helpdesk) and monitor the temperature over several days.
  2. Check that the physical, management and personal controls referred to above have been considered.
  3. Consider whether the thermal conditions being complained of are the result of short periods of excessively hot weather, or indicate a significant problem with the work environment.

If all reasonable steps have been taken, further action may be necessary if more than 15% of staff are complaining of being too hot or too cold.

  1. Seek advice from the Estates Management Section on dealing with problems such as draughts or problems opening windows.
  2. If you have done all that is within your control, but have assessed that there is still a significant ongoing problem, you should raise it with your Head of Department or Health and Safety Liaison Officer / Departmental Health and Safety Officer.

The Estate Management Section can assist with monitoring thermal conditions such as temperature and humidity over a period of time. They will also be able to give advice on possible solutions to obvious problems, such as action to deal with draughts.

Heads of Department or Health and Safety Liaison Officers will need to confirm that the manager has taken reasonable steps within his/her control to mitigate the problems. If so, and there is still clearly a significant problem with the thermal environment, the Estates Management Section should be asked to investigate reasonably practicable solutions.

Air conditioning

The University has to balance health and safety with the need to control costs and protect the environment. Air conditioning can also bring different thermal comfort problems or health risks if not correctly maintained. For these reasons air conditioning is only permitted in certain circumstances and it would normally only be considered if the combined effects of the heat input from people, lights and machinery cause the room temperatures to rise more than 5ºC above the ambient temperature. For further information refer to the University's Energy PolicyEnergy PolicyEnergy Policy.

Working in the sun / outdoors

Exposure to the sun can cause skin damage including sunburn, blistering and skin ageing. In the long term it can lead to an increased risk of skin cancer. Sun protection is important as sunburnt skin is damaged skin.

Hot and humid conditions, coupled with physically demanding work, can also lead to heat stress. Managers responsible for staff who are required to work in the sun need to consider the risks as part of their risk assessment.

Unnecessary exposure can be avoided by:

  • wearing long sleeve shirts or loose clothing with a close weave
  • wearing hats with a wide brim
  • taking more frequent rest breaks
  • taking breaks in the shade whenever possible
  • scheduling work to cooler times of the day
  • where possible, providing shade where work tasks are being undertaken

If your staff work outside, encourage them to check their skin regularly for unusual spots or moles that change size, shape or colour and seek medical advice promptly if they find anything that causes them concern.

Further information

Working in extreme temperatures

Heat stress

Heat stress may occur in work environments where excessive temperatures are created by the work process (eg catering kitchens or working outdoors in very hot conditions) and can lead to symptoms such as:

  • poor concentration
  • muscle cramps
  • heat rash
  • fainting
  • heat exhaustion - fatigue, giddiness, nausea, headache, moist skin
  • heat stroke - hot dry skin, confusion, convulsions and eventual loss of consciousness

Manager responsibilities

Managers responsible for activities where there is a risk of heat stress should carry out a risk assessment if the nature of the work activity or environment means there is a risk of heat stress. It is recommended that the HSE guidance on assessingrisks associated with heat stress is followed.

Cold stress

Measures to control risk from cold environment includes:

  • job rotation
  • provision regular rest breaks in warm rest areas
  • provision of suitable personal protective equipment

Please refer to the HSE for further guidance on working in excessively cold environments:

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