Extreme temperature risks on construction sites
Extreme heat and cold must be planned for as workplace risks, not treated as ordinary weather inconvenience. Before work starts, check the forecast and actual site conditions, speak with the crew, assess the task and set controls, monitoring, stop-work triggers and an emergency response.
The ACT's approved Managing the Risks Associated with Extreme Temperatures Code of Practice gives practical direction for ACT workplaces. Builders and subcontractors elsewhere can use it for orientation, but local requirements vary. Check current legislation and regulator material for the jurisdiction where the work is performed. A national Model Code is also general orientation and does not automatically apply as law in every jurisdiction.
Information current: 7 August 2026.
Main hazards to look for
Heat risk is more than the air temperature. Direct sun, humidity, poor airflow, radiant heat from concrete, metal or plant, enclosed spaces, heavy physical work and heat-retaining PPE can combine to overload a worker. Outcomes can include dehydration, cramps, fainting, heat exhaustion and heat stroke. Solar ultraviolet radiation is a related but separate outdoor hazard.
Cold risk can come from low temperatures, wind, rain, wet clothing, cold surfaces, refrigerated areas or long periods of low activity. It can lead to loss of concentration and coordination, numbness, trench foot, frostbite or hypothermia.
The same conditions can affect people differently. Acclimatisation, workload, clothing, hydration, health, medicines, age and fatigue can all change the risk. Invite workers to raise relevant needs privately and act on the information.
Sort this before work starts
A practical pre-start review should cover:
- forecast temperature, humidity, wind, rain and expected changes through the shift
- actual conditions at the work face, including shade, airflow, reflective surfaces and heat-producing plant
- task intensity, duration, access, isolation and PPE requirements
- drinking water, shaded or temperature-controlled recovery areas and suitable amenities
- new starters, workers returning after time away and anyone not acclimatised
- who will monitor conditions, when controls escalate and who can pause or stop work
- first aid, communications, transport and emergency arrangements.
For ACT building and construction work, the Code says site stop-work criteria should consider forecasts above 37 degrees Celsius. It also makes clear that heat-related illness can occur at lower temperatures. Treat that figure as part of a site-specific assessment, not as permission to keep working until a number is reached.
Controls and documents that should work together
Start with higher-order controls. Eliminate exposure where reasonably practicable, or reschedule, relocate or mechanise the task. Use shade, ventilation, insulation, barriers, cooling or heating, and separate workers from hot or cold sources. Then support these measures with work-rest cycles, job rotation, adjusted pace, shorter exposure, hydration, supervision and buddy checks. Select suitable PPE for the residual risk and account for the extra heat load or movement restriction it creates.
A temperature management plan is useful when conditions can change during the day. It should record the assessed hazards, agreed trigger points, controls for each level, monitoring method, responsible people, communication process and emergency actions. Keep it connected to the site's risk assessment, daily pre-start, toolbox talks, training records and emergency plan.
A SWMS commonly applies when the job includes high risk construction work. Extreme temperature exposure does not replace the need to identify the high risk construction activity. Where temperature can affect that work, reflect the hazard and controls in the SWMS or clearly link the SWMS to the site-specific temperature plan. For other work, a risk assessment, JSA, site plan or safe work procedure may be the more suitable record.
Review controls when conditions, tasks or crews change, after an incident or near miss, or when workers report that the plan is not working.
Warning signs mean act early
Heat warning signs include heavy sweating, headache, thirst, cramps, nausea, dizziness, unusual fatigue, poor judgement, confusion, collapse or very hot skin. Cold warning signs include persistent shivering, clumsiness, slurred speech, confusion, drowsiness, numbness or pale, waxy skin.
Stop the person's work, move them to a safer temperature-controlled area, provide first aid and follow the emergency plan. Severe confusion, collapse, suspected heat stroke or hypothermia requires urgent medical help. Do not leave an affected worker alone.
How Blue Safe can help
Blue Safe provides compliant WHS documents tailored to the client's activities, applicable Australian WHS/OHS requirements, jurisdiction and industry. Blue Safe guarantees the document compliance of the WHS documents it provides, including eligible customer documents after Blue Safe has reviewed and upgraded them.
For extreme-temperature work, this can include a tailored risk assessment, temperature management plan, SWMS content where high risk construction work is involved, site procedures, toolbox material and supporting registers. Customers actively put the compliant documents into practice through controls, consultation, training, actions, records and evidence.