Temperature extremes risk management procedure

1 Purpose

These guidelines are to assist with the management of the work environment and the comfort of staff during varying climate conditions.

2 Application

Thermal comfort is defined as: "that condition of mind which expresses satisfaction with the thermal environment". Each person is the expert on their own thermal comfort. A person's perception of thermal comfort is affected by air temperature, air movement (speed), humidity, clothing, activity level (i.e. the amount of physical work done), mean radiant temperature (the average temperature of the walls, floor, windows, etc) and many other factors.

3 Legislation

  • Occupational Health & Safety Act 2004

4 References

  • Code of Practice for Workplaces
  • Occupational Health & Safety Regulations 2007
  • NHRMC Effects of heat on health comfort and performance
  • Thermal Comfort in Winter
  • Thermal Comfort and Heat Illness

5 Responsibilities

5.1 Managers / Supervisors

Monitor the effect of heat on staff members during summer months.

Supervisory staff must be aware of forecast periods of excessive heat or cold, and arrange work programs accordingly.

5.2 Staff / Students

Notify supervisor if experiencing thermal discomfort.

5.3 Property and Campus Services

For new structures sponsored by Project Services, they can advise on the design and construction of airflow, ventilation, control of air conditioning plant and other building design factors.

For existing structures maintained by Infrastructure Services, they can advise on the ongoing maintenance of airflow, ventilation, control of air conditioning plant and other building design factors.

6 Procedure and Guidelines

6.1 Procedures to minimise thermal discomfort

The four most important environmental factors contributing to thermal comfort are air temperature, humidity, mean radiant temperature and air speed.

Temperature ranges of 20°C to 26°C are considered suitable for performing light or sedentary work in temperature-controlled indoor working environments. Most buildings occupied by University of Melbourne staff, students and residents, where Heating Ventilation and Air Conditioning (HVAC) is controlled by the University, have heating in winter up to 20°C and cooling in summer down to 26°C.Work programs should be arranged to take into account extended periods of excessive heat or cold. If practicable, work could commence and finish at times that avoid the greatest heat.

Other considerations for thermal discomfort are:

  • the time staff are exposed to hot tasks is reduced through job rotation (frequent brief exposures are less stressful than fewer longer exposures);
  • arranging extra ventilation to increase air movement is arranged;
  • doors and windows are closed to the heat for all or part of the day to prevent hot winds entering the room or building;
  • heat generating equipment such as screen-based equipment photocopiers and incandescent lights are turned off, where practicable;
  • windows are covered with either blinds or reflective coating; and
  • fans are used in areas of low ventilation.

6.2 Safety Information

Staff are encouraged to take frequent cool drinks and discouraged from drinking alcoholic or caffeine based drinks. Departments should ensure that there is cool water close to the affected area.

Staff should be aware of compounding factors which can increase susceptibility to heat stress, such as obesity, pre-existing heart or circulatory problems, dehydration, fever or diarrhoea.

6.3 Working Outdoors

Staff that are most likely to experience thermal discomfort work in buildings without adequate temperature regulation or are required to work outdoors on hot days. Heads of Department and other managers have a responsibility to monitor working conditions and when working in heat becomes difficult, to direct that certain tasks cease, allow staff to go home or move to a cooler environment.

Outdoor workers should take the following precautions:

  • use protective clothing, particularly covering the head. Head coverings should be wide brimmed hats rather than caps;
  • wear sun glasses (UV protective safety glasses) for eye protection;
  • use protective lotions on exposed parts of the body;
  • arrange work patterns that maximize work in shady areas;
  • avoid heavy work during the hottest part of the day;
  • use personal water canteens;
  • drink 250 ml of water every half-hour.

6.4 Cessation of Work

Although this policy does not specify the actual temperatures to be reached before work should cease, managers should assess working conditions and the extent of staff discomfort on a regular basis. This is particularly important on the third and fourth days of periods where the outside temperature has been around 35°C. On the basis of that assessment managers have the discretion to either place limitations on the work of their staff or to put a stop to work.

Where, after implementing procedures to minimise thermal discomfort, working conditions continue to be adversely affected by prolonged, extreme heat, heads of department and/or managers may, within their own discretion, decide to close the workplace and send staff home under special leave arrangements.

Please note that travelling home in hot conditions can also be hazardous. Heat distressed staff should be encouraged to attend the University's Health Service or their own doctor.

6.5 Staff Suffering Heat Stress

Conditions in Melbourne during summer can be extreme. In some circumstances these conditions may cause thermal distress which can lead to heat stress. This is especially true if people do not take appropriate precautions.

Heat stress occurs in situations where a person's core temperature rises above 38°C. Body temperature is regulated by the blood flowing from the core (abdomen, heart, brain) to the skin where the heat is dissipated by radiation, convection and evaporation to the environment. Heat stress may occur in environments where there is a combination of two or more of the following:

  • high temperature (e.g. summer);
  • high thermal radiation (e.g. foundries);
  • high humidity (e.g. mines);
  • a high level of activity (e.g. manual labour);
  • excessive or impervious clothing.

Under these conditions heat loss may no longer be in balance with heat production and heat related illness such as heat cramps, heat exhaustion, heat stroke may occur. There are very few work environments at this University that could give rise to heat stress.

Certain medical conditions such as diabetes symptoms, vomiting or diarrhea can increase during very hot weather. In addition, medical treatments, and medications may increase the risk of heat stress from heat exposure.

Staff who are distressed by the climatic conditions should report to their supervisor. The supervisor should consider:

  • moving the staff member to a cooler environment;
  • encouraging rest breaks in a less heat-stressful environment;
  • allowing the staff member to go home under special leave provisions.

7 Document Control

Established by: OHSC on 8 November 2002.
Date: 23 February 2016. Version 1.3 / Authorised: Associate Director, Health & Safety
Next Review: 23 February 2019 / (c) The University of Melbourne - uncontrolled when printed.

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