Extreme heat

Extreme heat is a critical health and safety hazard in many workplaces, whether work is performed indoors or outdoors. The World Health Organisation report Climate change and workplace heat stress: technical report and guidance highlights extreme heat as a growing occupational hazard driven by climate change, and emphasises the need to protect workers, especially those in manual roles.

This page is about specific extreme heat risks. Read more about duties and managing risks related to extreme weather.

Extreme heat risks

To find out if heat creates risks in the workplace, consider the effects, both in isolation and cumulatively, of the following potential hazards:

• air temperature
• air flow
• humidity (which can affect a person’s ability to cool)
• whether spaces are confined or open
• field work in hot climates
• radiant heat sources (for example, direct or reflected sun, a concrete or metal roof, hot machinery or appliances)
• air movement or wind speed
• work requirements and workloads (for example, physical or mental exertion, intensity and duration of work, ability of individual worker to pace the work)
• workers’ physical fitness, including acclimatisation and pre-existing conditions
• worker clothing and PPE (for example, does it trap heat, impair evaporation of sweat or otherwise increase the risk of heat-related illness)
• other workplace factors that generate or trap heat.

Heatwaves

Heatwaves can occur anywhere in Australia, and are defined by unusually hot maximum and minimum temperatures over 3 days. Heatwaves can increase WHS risks to workers by impacting their ability to perform work safely and effectively, due to:

• reduced sleep quality on warmer nights
• reduced ability to cool
• increased worker fatigue.

Heat-related illness

Heat-related illness describes a range of progressive heat-related conditions including dehydration, fainting, heat rash, heat cramps, heat exhaustion and heat stroke. If the body has to work too hard to keep cool or starts to overheat, this can lead to heat-related illness.

Take preventive action and seek first aid early if any of these symptoms arise while working in heat:

• feeling hot, weak and fatigued
• dizziness (particularly when standing)
• headache
• confusion
• loss of concentration, poor judgement, irritability
• clumsiness, slower reaction times
• overly thirsty, dark yellow urine
• nausea and vomiting
• rapid breathing and breathlessness
• clammy skin, overly sweaty
• fast, weak pulse rate, palpitations
• tingling, numbness of fingers and/or toes
• visual disturbance
• difficulty speaking or slurred speech
• seizures and unconsciousness (in extreme cases).

If any of these symptoms arise, immediately:

• move the worker to a cool place with circulating air
• loosen tight clothing and remove unnecessary garments (including PPE)
• drink frequent, small amounts of cool water
• seek immediate medical advice if symptoms don’t improve.

Heat stroke

The most serious type of heat-related illness is heat stroke. Heat stroke is a medical emergency.

Symptoms of heat stroke include:

• rapid pulse, difficulty breathing
• headache, dizziness, or visual disturbances
• red, hot or dry skin
• a sudden rise in body temperature (above 40° C)
• nausea, vomiting, cramps
• stopped or reduced sweating
• intense thirst
• clumsiness, disorientation, irritability or confusion
• fainting, seizure, unconsciousness
• stopped breathing or no pulse.

If heat stroke is suspected, call 000 and request an ambulance immediately.

See Safe Work Australia’s advice and guidance on first aid for heat-related illness.

Individual differences

The way heat affects workers varies from person to person, influenced by:

• general health and fitness
• body weight (being overweight or obese can make it more difficult to cope with heat)
• age (in particular, workers over the age of 55 are less able to work in hot environments and workers under the age of 25 may be more susceptible to heat-related illness)
• prescription drug use
• illicit drug or alcohol use
• pregnancy
• medical conditions such as heart or lung disease or diabetes.

PCBUs must take a risk management approach to prevent heat-related illness in consultation with workers and HSRs.

Safety measures

PCBUs must first consider whether it is reasonably practicable to eliminate the risks associated with extreme heat by, for example, cancelling or rescheduling the work.

Engineering controls

Where a WHS risk arising from extreme heat cannot be eliminated, engineering controls may be effective at minimising the risk. These may include:

• setting up shade tents
• installing artificial cooling such as air-conditioning
• insulating buildings and cladding sources of radiant heat
• replacing heat-producing machinery with machinery that produces less or no heat
• isolating hot machinery or surfaces by using shields, barriers and guards
• ensuring good air flow – for example, by installing fans or generating air movement via windows and vents, particularly in humid conditions
• removing heated air or steam from hot processes using local exhaust ventilation
• providing air-conditioned, shaded or cool break areas as close as possible to the work site
• reducing radiant heat, for example, by allowing a plant to cool down before use
• providing accessible cool drinking water or, when necessary, electrolyte solutions.

Administrative controls

These risk controls can be complemented by administrative control measures such as:

• scheduling more physically demanding activities for cooler parts of the day (recognising that heat stress is still possible even in cooler conditions)
• organising work to minimise physically demanding tasks (for example, by conducting work at ground level to avoid climbing up and down stairs or ladders)
• modifying targets and work rates to reduce physical exertion
• ensuring workers will not be working alone, or, if not possible, monitoring them
• supervising young workers and those new to the workplace, with supervisors able to monitor WHS and other work practices, answer questions and provide guidance.

PPE

PPE can be effectively used in conjunction with higher level controls to minimise residual risks associated with working in heat. If practicable, modify uniforms or required dress codes so workers can wear cooler, more breathable clothing. PCBUs can provide wearable personal cooling systems, such as water-cooled garments, air-cooled garments, cooling vests and wetted garments.

Required PPE can increase the risk of heat-related illness. For example, heavy protective clothing and masks can trap heat close to the body. PCBUs should consider the type of PPE being provided as well as the length of time an individual is wearing PPE, their work rate, acclimatisation level and environmental conditions. Consider additional control measures, such as increase in break times, when workers are required to wear PPE that increases the risk of heat-related illness.

Emergency plans and first aid

PCBUs must ensure that their emergency plan is suitable for the work and workplace. For example, if a worker collapses in a confined space, ensure there are procedures in place to rescue them without delay.

The severity of heat-related illness is impacted by access to support services, such as first aid and emergency services. PCBUs should ensure remote or isolated workers can contact and access that help.

Training, information and supervision

Workers must be trained to be able to carry out their work safely. For example, workers should be trained to:

• identify and report hazards associated with heat and heat-related illness
• understand how to prevent heat-related illness
• recognise symptoms and signs of heat-related illness in themselves and others
• call for assistance if necessary
• look out for each other’s wellbeing
• modify work intensity and take more regular breaks when working in heat
• drink sufficient water to stay hydrated
• recognise the dangers of diuretic drinks
• be aware of individual risk factors
• understand acclimatisation
• recognise the potential dangers associated with the use of alcohol and/or drugs when working in heat.

Worker actions

To help prevent heat-related illness, workers can:

• ensure they are fit and able to do the work
• ensure they are well-hydrated before starting work
• eat regular meals and snacks to replace salt and electrolytes lost through heat
• notify their employer if they have a medical condition that may increase susceptibility to heat-related illness (such as heart disease, high blood pressure, pregnancy, respiratory disease, diabetes and skin diseases)
• follow employer instructions and comply with any safety requirements
• if working outdoors, always wear a hat and sunglasses, and apply sunblock regularly
• take regular breaks to cool down and seek shelter in air conditioned or well-ventilated environments
• drink least a small cup (200 ml) of cool water every 15–20 minutes.
• avoid soft drinks, caffeine or alcohol, which are dehydrating
• carry water and drinks in a portable esky with ice, dipping a towel into the icy water and applying to skin, back of neck and face as needed
• know the signs of heat-related illness and seek help immediately if you or a colleague is affected.

Download the fact sheet Working in heat (PDF, 213.3 KB)

Workers should report any concerns to their supervisor or a HSR.

Solar ultraviolet radiation protection

Workers who spend all or part of the day working outdoors are at risk of skin cancer and eye damage. The risk of exposure to solar ultraviolet radiation (UVR) may not be obvious for some workers, such as vehicle drivers. Workers that may be in and out of the sun during the day may have intermittent exposure. Accumulated exposure creates a risk to their health and safety.

While the sun is the main source of UVR, it also comes from phototherapy, solariums, fluorescent, neon and halogen lighting, industrial arc welding, UVR lamps, black lights, germicidal UVR lamps and UV lasers.

The health and safety risks associated with exposure to solar UVR at the workplace should be managed by:

• identifying and assessing the solar UVR exposure risk to workers
• eliminating or minimising, so far as is reasonably practicable, the risk by implementing and reviewing sun protection control measures
• providing information, instruction, training and supervision.

For more information, see:

• Guide on exposure to solar ultraviolet radiation (UVE) – National Guidance (Safe Work Australia)

State and territory-specific guidance

• SafeWork NSW – Heat – working in extreme heat
• SafeWork NSW – Working in extreme heat: the facts
• SafeWork SA – Heat and UV
• NT WorkSafe – Working in heat
• WorkSafe QLD – Heat stress
• WorkSafe Victoria – Sun protection
• WorkSafe Western Australia – Working safely in hot conditions
• WorkSafe Tasmania – Hot and cold environments
• WorkSafe ACT – Working in extreme hot or cold temperatures