Is there a maximum temperature where workers are required to stop work? 

No. A single ‘stop work’ temperature can’t account for all the factors that make working in heat hazardous, including: 

• humidity 

• air flow 

• physical intensity and duration of the work, and  

• whether workers are physically fit and acclimatised to the conditions.  

 
Instead, PCBUs must eliminate or minimise risks so far is reasonably practicable. This may include cancelling or rescheduling certain work tasks until conditions are cooler.  

 
PCBUs must provide and maintain a workplace that is without health and safety risks. Work should be carried out in a comfortable temperature that suits the work. Air temperatures that are too high can contribute to fatigue and heat-related illness.  

What are the risks of a heatwave, and how can those risks be managed?   

A heatwave occurs when the maximum and the minimum temperatures are unusually hot over at least a three-day period. Heatwaves may pose more risks to workers due to: 

• warmer nights contributing to reduced sleep quality  

• high temperatures earlier in the day and lasting longer, and  

• fatigue affecting workers’ ability to perform work safely and effectively.  

In a heatwave, PCBUs should carry out additional risk assessments and put control measures in place.  

Potential controls include: 

• scheduling work to cooler parts of the day 

• minimising physical effort requirements and  

• performing work in safer locations. 

• ensuring workers have access to  

• cool fresh water, 

• air-conditioning or fans (if possible), or  

• access to shade for outside work.  

Where possible, workers shouldn’t work alone. If they must, establish procedures for monitoring them and ensuring they can easily seek help.  

If working in a heatwave is necessary, PCBUs should plan tasks so workers can self-pace their work. 

Your local health and emergency service authorities can provide more information on heatwaves.  

What can workers do if the work is unsafe due to the heat? 

Health and Safety Representatives (HSRs) can direct a worker in their work group to cease unsafe work. HSRs can do this if: 

• they have a reasonable concern that a worker would be exposed to a serious health and safety risk from an immediate or imminent hazard, and 
• they have consulted and attempted to resolve the issue with the business or undertaking. This does not apply if the risk is so serious and immediate or imminent that it is not reasonable to consult first. 

HSRs must inform the workplace of any direction that has been given to cease unsafe work. HSRs can only stop unsafe work if they have completed their training under the model WHS laws.  

For general guidance, see the Worker Representation and Participation Guide. For more specific guidance on these rights, contact your local WHS regulator. 

What are heat-related illnesses? 

Prolonged or intense exposure to high temperatures can lead to heat-related illnesses. These occur when your body is no longer able to maintain a healthy body temperature. Heat-related illnesses may include: 

• heat exhaustion 

• heat cramp  

• dehydration  

• fainting, and  

• heat stroke.  

 
People who are most at risk of heat related illness are: 

• young (under 25) and older workers 

• pregnant women 

• people with physical illness such as heart disease, and 

• workers who are not acclimatised to working in heat. 

Heat-related illness is progressive and can be life threatening if left untreated. Supervising or training workers to recognise the common symptoms of heat-related illness can help ensure first aid is provided promptly.  

 
The symptoms of a heat-related illness may include:  

• dizziness  

• sweating  

• visual disturbances  

• fainting  

• nausea, and 

• muscle cramps  

 
Are there risks for working in heat indoors? 

PCBUs must protect worker health and safety in all work environments. Heat-related illness can also arise from indoor work. This can arise from high thermal radiation and humidity, such as those in commercial kitchens and laundries. 

High air temperatures and humidity can contribute to fatigue and heat-related illnesses. The temperature in the work environment should be comfortable and suit the type of work. For example, sedentary work may still be safer in higher temperatures.  

PCBUs must manage the risk of heat-related illnesses. Some control measures for managing heat indoors include:  

• removing heated air or steam from hot processes using local exhaust ventilation  

• isolate workers from indoor heat sources. For example, insulate plant, pipes and walls  

• increasing air movement using fans or installing air-conditioners or evaporative coolers 

• scheduling work to cooler parts of the day. For example, conduct work in hot places such as roof cavities first thing in the morning 

How do I know if a worker is acclimatised to heat? 

Acclimatisation means that the body is starting to adapt to heat. An acclimatised worker may: 

• sweat more efficiently, and 

• be better at maintaining a normal body temperature.  

You should not rely on acclimatisation as a control measure, as it is different for every person. Acclimatisation programs should be undertaken in consultation with a professional, such as an occupational hygienist.  

Workers who are not acclimatised or are returning after being away for a week or more are at a higher risk of a heat-related illness. 

What are some ways of minimising risks of working in heat? 

As a PCBU, you must manage risks in the workplace, so far as is reasonably practicable. The risk management process involves several steps, including: 

• Identifying hazards—find out what could go wrong and what could cause harm.  

• Carry out a risk assessment to determine the likelihood and severity of the risk. If the risks and controls are already well known you may not need to do a risk assessment.  

• Controlling risks—implement the most effective control measures. The control measures must be reasonable in the circumstances.  

You must first aim to eliminate hazards. For example, cancel outdoor work when temperatures are high.  

If elimination is not possible, consider substitution, isolation and engineering controls. For example: 

• substitute the hazard for something safer. For example, swap physical work for work with machines. 

• isolate the risk from workers: separate workers from hot machinery, and  

• engineering controls. For example, setting up shade tents outdoors and using air conditioners indoors.  

If a risk still remains, you must put administrative control measures in place.  

Administrative control measures include processes and training. For example, schedule more physical tasks to cooler parts of the day. 

Personal protective equipment (PPE) should be control any remaining risks. For example, provide breathable and light clothing.  

Review the controls you have implemented to ensure they remain effective. 

As a PCBU, you must manage risks in the workplace, so far as is reasonably practicable. The risk management process involves several steps, including: 

• Identifying hazards. Find out what could go wrong and what could cause harm. 

• Assessing risks, if necessary. Think about the harm each hazard could cause, how serious it could be and the likelihood of it happening. 

• Controlling risks. Implement the most effective control measures that are reasonably practicable in the circumstances. 

• Reviewing control measures to ensure they are working as planned. 

You must first aim to eliminate hazards. For example, cancel outdoor work when temperatures are high.  

If elimination is not possible, consider substitution, isolation and engineering controls. For example: 

• substitute the hazard for something safer. For example, swap physical work for work with machines. 

• isolate the risk from workers: separate workers from hot machinery, and  

• engineering controls. For example, setting up shade tents outdoors and using air conditioners indoors.  

If risks still remain, you must minimise them using administrative control measures. For example, schedule the more physical tasks to cooler parts of the day. 
You must also provide training on safe work procedures. For example, train workers on the safe use of machinery.   

Personal protective equipment (PPE) should be control any remaining risks. For example, provide breathable and light clothing.  

Review the controls you have implemented to ensure they remain effective.