The duty, in plain terms
Australian work health and safety law puts the responsibility on the PCBU, the person conducting a business or undertaking. In a warehouse or workshop, that is usually the employer. The duty is to eliminate or minimise risks to health and safety so far as is reasonably practicable.
What does reasonably practicable mean in practice? It means looking at what is known about the risk, what controls are available, and what is reasonable in your circumstances. A duty holder who has assessed the heat in their building, consulted the people working in it, and put sensible controls in place is doing what the law expects. One who has done nothing and is waiting for a number on a thermometer is not.
Consultation is part of the duty too. Workers who spend their shifts in the building know better than anyone where the heat collects and which tasks push people closest to their limit. Australian work health and safety law requires you to consult them on matters that affect their health and safety, and heat is squarely one of those matters.
None of this needs to be complicated. It needs to be genuine, documented, and done before the first hot spell of the season, not after someone goes home unwell.
There is no legal maximum temperature, and why that matters
The first question most people ask is some version of “how hot is too hot before we have to stop work?” The honest answer is that there is no single legislated stop-work temperature in Australia. Safe Work Australia’s position is that one temperature cannot account for all the factors that make working in heat hazardous, and the WHS Regulation does not state a precise figure at which workers should stop.
This matters because it changes what you are actually managing. Heat risk is the product of several things acting together: air temperature, humidity, radiant heat from a hot roof or machinery, air movement, how heavy the work is, and what workers are wearing. Two buildings at the same reading can carry very different risk, and the same building can change hour to hour as the sun moves across the roof.
So the obligation is not to watch a thermometer for a magic number. It is to assess the conditions in your building, identify the risks, and put controls in place through the hierarchy of controls. That is a more demanding standard than a threshold, but it is also one you can actually meet with decisions that suit your building and your work.
What makes a warehouse or workshop hot
Most large industrial buildings heat up through the roof. Metal cladding absorbs radiant heat all day and re-radiates it downward, and warm air rises and sits in a stacked layer under the ridge that nobody working at floor level benefits from. In a tall shed, the air two metres off the slab can be markedly different from the air at the apex, and the warmest air stays up there where it does nothing useful.
Process heat adds to it. Machinery, compressors, welding bays, ovens and kilns each dump heat into the space continuously, and in a workshop those sources often sit close to where people work.
Low air movement is the third piece. A big open volume with still air means sweat sits on the skin instead of evaporating, which is the body’s main cooling mechanism doing very little. That is also why humidity matters so much: the same air temperature is more dangerous on a humid day because sweat evaporates less readily and the body sheds heat more slowly. A building that seems tolerable in dry summer conditions can become genuinely hazardous when the moisture comes in.
The hierarchy of controls, applied to a hot building
The hierarchy of controls orders interventions from most to least effective, and it is worth walking through honestly.
At the top, eliminate or substitute. If a process can be moved outdoors, done in a cooler shift, or done with equipment that generates less heat, that beats anything downstream. Often it cannot be, and that is fine.
Next come engineering controls, which is where most of the real work in a hot building happens. Insulate the roof to cut radiant gain. Clad or shield hot surfaces near work positions. Improve natural ventilation so the stacked hot air can escape at the ridge. And increase air movement across work areas, which Safe Work Australia’s guidance names as a control measure, alongside artificial cooling and good airflow through windows and vents, particularly in humid conditions. This is where warehouse ceiling fans and workshop and shed fans fit. A large slow-moving ceiling fan moves a high volume of air across the whole floor at low running cost, and our industrial fan installation is handled by a licensed electrical contractor so the fan, the mount and the wiring are done as one job.
Then administrative controls: reschedule or cancel heavy work until conditions are cooler, rotate tasks, provide rest breaks, and keep cool drinking water available.
PPE sits last. It protects against specific hazards but does little for heat.
Be clear about the sequencing: a fan is one engineering control among several. It is not, on its own, a heat management plan, and it does not remove the need for the administrative controls above it in the day-to-day sense.
Where air movement helps, and where it does not
Air movement helps because it increases evaporative cooling from the skin. A worker standing in a moving column of air sheds heat noticeably better than the same worker in still air, which is why fans show up in Safe Work Australia’s listed measures for managing heat, particularly in humid conditions. The coverage each size reaches is listed on the industrial ceiling fans range.
But the limits deserve stating plainly. Moving air does not lower the air temperature in the building. It does not extract fumes, dust or smoke, and it should never be treated as ventilation for airborne contaminants, which is a separate problem needing separate controls. And at very high air temperatures, moving hot air over skin stops helping and can start working against the body, because the air is no longer cooler than skin temperature and evaporation cannot keep up.
A fan earns its place as part of a layered approach: insulation and ventilation doing the structural work, air movement making the floor tolerable, and administrative controls covering the days when none of the hardware is enough. Anyone relying on a single measure is relying on the wrong thing.
Hydration, rest and recognising heat illness
Cool drinking water must be available to workers, and they should be encouraged to actually drink it through the shift rather than only when they feel thirsty. Rest breaks in a cooler spot, which might be an air-conditioned office, a shaded area or simply the calmest corner of the building, let the body recover between periods of heavy work.
Consultation matters here as much as anywhere else. Workers will tell you when the water point has run dry, when breaks are being skipped to hit a deadline, and which part of the floor feels worst in the afternoon.
If anyone suspects heat illness, in themselves or in a workmate, the right response is to seek medical advice and follow their own workplace procedures. Heat illness is not something to diagnose or manage informally on the floor.
Building a plan you can show someone
Write it down. Assess the building: where the heat comes from, where people work relative to it, what air movement exists. Consult the workers, and record that you did. List the controls you have chosen across the hierarchy, including the ones you considered and rejected and why. Put dates against each item, including who is responsible and when it will be done.
Then review it after the first hot spell, because the plan you wrote in April will have gaps that only a 38-degree week reveals.
This is what a regulator or an insurer expects to see when they ask how you manage heat: not a perfect building, but a documented, current process showing you assessed the risk, involved your workers, and acted. It takes an afternoon to put together and it is worth far more than any single piece of equipment.
