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Heat related illness incident

In April 2023, a farm worker was found deceased at a rural property. The worker was conducting outdoor labouring work at a property on a hot day.

Early investigations indicated the worker had complained of cramps while working outside and had returned to a shed on the property to rest and hydrate. It appears he attempted to leave the farm but was later found deceased.

Investigations are continuing.

Safety issues

Working in heat can be hazardous and can cause harm to workers. The human body needs to maintain a core body temperature of approximately 37 degrees.

If the body has to work too hard to keep cool or starts to overheat, a worker can suffer from a heat-related illness. This is a general term to describe a range of progressive heat-related conditions including fainting, heat rash, heat cramps, and heat stroke.

Some common effects of working in heat include:

  • Heat rash, leading to skin irritation and discomfort.
  • Heat cramps resulting from heavy sweating without replacing salt and electrolytes.
  • Fainting, particularly when workers stand or rise from a sitting position.
  • Dehydration from increased sweating if workers aren’t drinking enough water.
  • Heat stroke occurs when the body can no longer cool itself. This can be fatal.
  • Burns can occur if a worker comes into contact with hot surfaces or tools.
  • Slips, as a worker will sweat more in hot conditions which can increase the risk of slips (for example, a worker might slip when using sharp tools if their hands are damp).
  • Reduced concentration, as heat can make it more difficult to concentrate, leading to confusion. This means workers may be more likely to make mistakes, such as forgetting to guard machinery.
  • Increased chemical uptake into the body may occur as the heat causes the body to absorb chemicals differently and can increase the side effects of some medications.

Ways to manage health and safety

Effective risk management starts with a commitment to health and safety from those who manage the business. If an incident occurs, you'll need to show the regulator that you’ve used an effective risk management process. This responsibility is covered by your primary duty of care in the Work Health and Safety Act 2011.

Use the hierarchy of controls to help decide how to eliminate and reduce risks in your place of work. The hierarchy of controls ranks types of control methods from the highest level of protection and reliability to the lowest. It’s a step-by-step approach to eliminating or reducing risks. You must work through the hierarchy of controls when managing risks, with the aim of eliminating the hazard, which is the most effective control.

Possible control measures to prevent similar incidents

Identify the risks

Heat-related illness risks aren’t just affected by temperature and humidity.

Assessing risks of heat-related illness requires accurate identification and assessment of:

  • workplace conditions
  • job requirements
  • individual worker attributes.

Examples of risk factors which also need to be taken into consideration include:

  • Exposure to direct and reflected sunlight, especially during the hottest parts of the day.
  • Amount of air movement such as natural and forced, in open or confined workspaces.
  • Radiant temperature of surroundings (environment, plant and equipment).
  • Clothing breathability and whether it inhibits the evaporation of sweat.
  • Personal protective equipment worn by the worker.
  • Physical manual work such as metabolic heat load, type and duration.
  • Hydration level of workers.
  • Access to cool rest areas.
  • Individual acclimatisation status (recent exposure to working in heat).
  • Worker factors including fitness levels, medical conditions, medications, and understanding heat risk factors (signs and symptoms of heat induced illnesses).
  • Geographical location and climate.

As conditions can change daily, risk assessment should be conducted regularly. Remember, the consequences of not managing risks can include permanent injury and death.

To assist businesses to meet their obligations, Workplace Health and Safety Queensland has a Heat stress (basic) calculator to assist with undertaking initial risk assessments. The WHSQ Heat stress webpage provides further risk assessment and control information.

Controlling the risks

There are two approaches to controlling the risk:

  • modify the environment to suit the work
  • modify work to suit the environment.

Look carefully at the control measures that can be used, some are more practical for certain situations than others. In most situations, multiple controls will be required.

Modifying the environment to suit the work

Control the source of the heat

  • Reduce the temperature of the source of heat (e.g., allow the section of plant or equipment to cool before work commences).
  • Insulate hot surfaces (can also provide protection from contact burns).
  • Clad or cover sources of radiant heat.
  • Use radiant heat shields or barriers (need to have good insulation properties and low emissivity/high reflectivity so they don't become hot).
  • Use shade barriers (e.g., temporary gazebos) over the work area to block heat from the sun.

Ventilation, air conditioning and air movement:

  • Remove or dilute hot/humid air and replace it with cooler/drier air. This is the most efficient method and can be achieved by either forced mechanical ventilation or naturally. It is especially important in hot and humid environments. Examples include:
    • mechanical ventilation which draws cool air from outside the work area to displace the hotter air.
    • exhaust or extraction fans to remove hot air.
    • natural ventilation via windows, doors, and roof vents/louvres.
  • Increase air movement in the work area (e.g., fans).
  • Use artificial cooling items such as evaporative coolers, air conditioning, vortex tubes, or chillers.

Modifying the work to suit the environment

Modify the work process:

  • Use mechanical aids such as cranes, forklifts, and earthmoving plant to reduce the workload.
  • Conduct work at ground level or organise work to minimise climbing up and down stairs and ladders.
  • Do the work indoors or in a shaded area.

Provide rest areas/refuges to escape the heat:

  • Use refuges for workers to escape the effects of hot environments.
  • Locate as near to the work area as possible.
  • Provide shelters (shelters can range from temporary gazebos through to insulated structures or cabins which are air-conditioned).

Administrative controls

  • Worker selection – workers who have become acclimatised to the work environment are at less risk than unacclimatised workers.
  • Scheduling of work – where possible, conduct the work:
    • In cooler parts of the year, especially where the work requires protective clothing.
    • At night, early morning, or late afternoon rather than midday.
  • Work-rest intervals:
    • Spend rest periods in a cool place with a plentiful supply of cool water for fluid replacement.
    • Remove protective clothing during breaks to allow workers to cool off.
  • Fluid replacement – critical when working in a hot environment, especially where hard work (metabolic work) is required:
    • Drink small volumes as frequently as possible during work.
    • Provide cool drinks or water as close as possible to the work area (if supplying drinks, make sure the workers actually like them).
    • Help workers to self-monitor their hydration status via hydration test strips and urine colour charts.
    • Encourage workers to avoid diuretic drinks immediately prior to starting work and to rehydrate between shifts.
    • Encourage workers to consume water at the start of the shift to maximise their hydration status.
    • Encourage the replacement of electrolytes in high sweat scenarios.
  • Buddy systems – trained workers can keep an eye on each other for signs of heat effects, reducing risks compared to isolated workers.

Personal protective equipment (PPE)

Clothing and particularly protective clothing can often have an adverse effect on the body's heat balance in hot environments by insulating the body and reducing evaporative heat loss. Impervious clothing can impede heat loss.

PPE can also help to reduce the risk of heat strain in some circumstances.

Examples include:

  • wearing a hat to protect from sunlight
  • vented safety eye wear (where safe to do so)
  • protective clothing (especially if made from natural fibre, will provide some protection against contact burns and radiation)
  • wearing light coloured (especially white, and reflective clothing) which absorb comparatively little radiant heat energy
  • wearing cotton gloves as a lining under regular gloves
  • wearing lightweight/cotton undergarments
  • using specialised cooled or conditioned personal protective clothing including:
    • air circulating systems
    • liquid circulating systems
    • ice cooling systems
    • reflective systems.

Train workers

Providing training is required for all workers likely to be working in hot environments, undertaking strenuous work at elevated temperatures, and those who wear impermeable protective clothing.

Training should include:

  • mechanisms of heat exposure
  • potential heat exposure situations
  • recognition of predisposing factors
  • importance of fluid intake
  • the nature of acclimatisation
  • effects of alcohol and drugs
  • early recognition of symptoms of heat illness
  • prevention of heat illness
  • first aid treatment of heat illnesses
  • self-assessment
  • how medical surveillance programs work and the advantages of employee participation.

The control measures put in place should be reviewed regularly to make sure they work as planned.

More information

Have you been affected by a workplace fatality, illness or serious injury?

For advice and support: