In February 2019, two workers were taken to hospital with one admitted for heat syncope (a mild form of heat illness). The workers had been preparing formwork for a concrete pour at a construction site. Three other workers also reported feeling unwell and were treated onsite by emergency services.
Early investigations indicate the workers reported feeling unwell while preparing the formwork during the morning, when the temperature was approximately 32 degrees. Conditions were being managed through work breaks, access to water and supervision. Investigations are continuing.
Preventing a similar incident
Heat stress is the total heat load on the body from sources including:
- ambient air temperature
- radiant heat from other sources (e.g. vehicles, equipment and hot-work processes)
- air movement
- relative humidity
- individual task requirements
- metabolic heat produced by the body because of physical activity.
Working in hot and/or humid environments can cause heat-related illness and in some cases this can be fatal. There is no recommended temperature limit at which work should cease as setting a safe or unsafe limit simply based on ambient air temperature is not appropriate due to the many variables associated with the onset of heat stress.
The risk is also not just related to temperature. There is a combination of factors that contribute to heat-related problems at work, including:
- exposure to direct sunlight, especially during the hottest part of the day
- exposure to reflected heat from construction materials, polished aluminium and glass
- strenuous tasks or work for sustained long periods
- exposure to additional heat from machinery
- inadequate cooling off, rest periods or insufficient water consumption
- climatic conditions (low air movement, high humidity, high temperature)
- clothing and personal protective equipment that reduces heat loss from the body
- workers not being used to carrying out physical work in hot conditions
- poor diet, vomiting, diarrhoea or alcohol and caffeine consumption
- fatigue related to inadequate or irregular sleep patterns.
A PCBU's responsibilities include:
- ensuring workers carrying out tasks in hot conditions can do so without risking their health and safety
- considering higher order controls, such as a safe system of work in line with other control measures, like sheltered rest areas and easily available cool water
- providing information, training and instruction to workers so they can recognise the early symptoms of heat-related illness, know how to follow safe work procedures and report any problems immediately.
A safe system of work should include an assessment of both the environmental conditions at the workplace and the physical well-being of workers, as well as ongoing monitoring and supervision in hot conditions, especially during very hot and humid weather.
The PCBU and workers should consult each other, and share information about managing health and safety. PCBUs must give workers who are, or are likely to be directly affected by heat exposure, a reasonable opportunity to express their views or raise issues. Consider conducting a walk-through survey of the workplace, and ask workers about their heat stress issues. Consider the work location's previous history of heat stress issues and under what circumstances they occurred.
The risk and severity of heat related illness will vary widely among workers, even under identical heat stress conditions.
You can prevent heat stress by:
- modifying the work environment:
- Reduce radiant heat by insulating hot surfaces, clad or cover sources of radiant heat, and use radiant heat shields, or barriers.
- Increase air movement by installing exhaust or extraction fans to remove hot air, opening doors and windows, installing fans and artificial cooling such as evaporative coolers, air conditioning, vortex tubes, or chillers.
- modifying the way work is carried out:
- Use mechanical aids such as cranes, forklifts and earthmoving plant to reduce the workload, conduct work at ground level to minimise climbing, and do the work indoors or in a shaded area.
- Provide rest areas/refuges as near to the work area as possible for workers to escape the heat by. You can use shelters from gazebos, insulated structures, or airconditioned cabins.
- Use administrative controls could include scheduling of work, rest intervals, fluid replacement and buddy systems.
- Provide personal protective equipment. Options include wearing a hat, vented eyewear, and specialised cooled or conditioned personal protective clothing.
Since 2013, on average each year 60 workers' compensation claims are accepted for workers affected by heat. Around 12 per cent are for a serious condition requiring five or more days off work. The construction industry accounts for about 25 per cent of heat-related claims.
The number of accepted heat-related claims is increasing, from an average of 50 claims per year for 2013-16 to an average of 75 claims per year for 2016-18.
Since 2013, we have issued 21 notices for issues involving people affected by heat stroke or heat stress.
- How to manage work health and safety risks Code of Practice 2011 (PDF, 1.02 MB)
- Managing the work environment and facilities Code of Practice 2011 (PDF, 0.7 MB)
- Heat stress information
- Heat stress calculator
- Guide for managing the risks of working in heat - Safe Work Australia