Every employer has a duty under s.2 of the Health and Safety at Work Act 1974 to ensure the health, safety and welfare at work of all employees, so far as is reasonably practicable. Part of this duty is the maintenance of an environment that is free from risk. A comfortable work environment will depend upon many factors, most importantly temperature, humidity levels and the rate of airflow. The Workplace (Health, Safety and Welfare) Regulations 1992 require temperatures in factories, offices, shops and other workplaces brought into existence from 1 January 1993 to be reasonable for the comfort of persons employed. It is suggested that 16°C is reasonable for sedentary work but where physical effort and work of a strenuous nature is undertaken, this may drop to 13°C (factors such as humidity, ventilation and thermometer positions should be taken into account).

For workplaces in use prior to 1 January 1993 the provisions contained in s.3 of the Factories Act 1961 and s.6 of the Offices, Shops and Railway Premises Act 1963 apply until 31 December 1995. These state that where sedentary work is undertaken a minimum temperature of 16°C must be achieved within one hour of starting work.

There is no statutory maximum temperature, although under the Fuel and Electricity (Heating) (Control) (Amendment) Order 1980 it is not permitted to specifically use energy to create a temperature greater than 19°C. The general duties under Health and Safety at Work etc. Act '74 require employers to ensure that work environments do not become excessively hot to the point that employees' health and safety is adversely affected.

Exceptions may be made where high or low temperatures would cause deterioration of goods, subject to suitable alternative arrangements for the welfare of employees. Where it is not reasonably practicable to provide heating throughout an area, such as where members of the public regularly come in and out, provision of localised heating for employees will be sufficient.

A thermometer must be on display in every factory workroom where light sedentary work is carried out. In offices and shops it is sufficient to locate a thermometer on each floor of the building.

There are some statutory controls over temperature and humidity, the primary purpose of which is to prevent risks arising from a process. Certain requirements related to humidity and temperature apply in the case of activities under the Hemp and Jute Spinning and Weaving Regulations 1907, the Flax and Tow Spinning and Weaving Regulations 1906, the Cotton Cloth Factories Regulations 1929 and the Jute (Safety, Health, and Welfare) Regulations 1948. Legislation also applies to other humid factories, as defined in s.176 of the Factories Act 1961.

The Health and Safety (Display Screen Equipment) Regulations 1992 state that display screen equipment must not produce excess heat which could cause discomfort to operators or users and that an adequate level of humidity must be established and maintained. Electronic equipment can be a source of dry heat that can affect the thermal environment at the workstation. Ventilation and humidity should be maintained at levels that prevent discomfort and problems of sore eyes.

For workers out of doors, in cold stores or in other hostile environments a risk assessment should be carried out as required by regulation 3 of the Management of Health and Safety at Work Regulations 1992 in order to identify and protect against risks presented by extremes of temperature. It may be found necessary to provide suitable shelters on outdoor sites, or personal protective clothing may be required to maintain a comfortable body temperature, in which case an assessment should be carried out under the Personal Protective Equipment at Work Regulations 1992.

RECORD KEEPING
It is advisable that the following information is recorded and kept.

1. Dates and details of maintenance of air conditioning and heating or equipment.

2. Actions taken in response to defects identified within a maintenance report.

3. Details of complaints made by employees concerning the thermal environment, for example:

(a) who made the complaint - an individual, a group or a whole office

(b) what part of the workplace is affected - exact location of problem

(c) what the complaint is about - temperature, humidity or draughts

(d) when the problem was raised - date, time of year (weather conditions outside)

(e) what the temperature was at the time of the complaint

(f) what the status of the air conditioning systems was at the time - functioning, not functioning, faulty

(g) other underlying reasons for the complaint, e.g. resistance to change, dissatisfaction with job or workstation, etc.

4. Action taken to rectify the cause of complaint at the time and proposed action to ensure user comfort and efficiency in the long term.