On this page Heat stroke: call an ambulance · No stop-work temperature, and why · Planning a pour around the heat · 32ºC: the line for a house slab
Heat stroke: call an ambulance
If you think someone may have heat exhaustion or heat stroke, call an ambulance immediately. Safe Work Australia’s signs and first aid follow in full.
“Heat stroke symptoms include:
- dehydration, thirst, and reduced or dark urine output
- sweating
- elevated body temperature
- weakness or fatigue
- headaches and dizziness
- nausea
- muscle cramps.
Severe symptoms include:
- the worker stops sweating
- skin can be pink, warm and dry, or cool and blue
- clumsiness or slower reaction times
- disorientation or impaired judgement
- rapid or short breathing
- rapid weak pulse, pounding pulse or heart palpitations
- tingling or numbness in fingers or toes
- visual disturbance
- vomiting or an unwillingness to drink.
- irritability and mental confusion
- collapse, seizures and unconsciousness
- cardiac arrest (the worker is unconscious, has stopped breathing and has no pulse).
Not all heat-induced illness symptoms will be present.”
First aid for heat-induced illness
- “Call 000 and evacuate by ambulance immediately
- Update the ambulance if the worker seizes or becomes unconscious and follow all directions given by emergency crew
- Follow all instructions given by ambulance operator
- If cardiac arrest occurs, follow DRSABCD action plan
- Move the worker to a cool place with circulating air.
- Lie the worker flat.
- Remove unnecessary clothing, including PPE.
- Loosen tight clothing.
- If practicable, immersion in a bath of cold water is the most effective cooling means possible.
- Immerse the worker (whole-body from the neck down) in a bath of cold water (preferably 1–7˚) for 15 minutes.
- Continuously observe the worker to ensure an open airway in case of any change in their level of consciousness.
- If cold bath is not available, or is not reasonably practicable to use, use a combination of the following as available:
- Cool the worker by splashing cool or cold water on their skin or sponging their skin with a damp cloth.
- Make a wind tunnel by suspending sheets around–not on–the worker’s body, and use a fan to direct gentle airflow over the worker’s body.
- Apply cold packs or wrapped ice to the worker’s neck, groin and armpits.
- Give an electrolyte solution with sugar– do not attempt to give oral fluid if the worker is not fully conscious.
Shivering is an automatic muscular reaction which warms the body. It will make the body temperature rise even further.
If the worker starts shivering:
Safe Work Australia, First aid for heat-related illness, reproduced unaltered under CC BY 4.0.
- stop cooling immediately and cover them until they stop
- once they have stopped, recommence first aid treatment.”
| Illness | What it looks like | First aid |
|---|---|---|
| Dehydration | Thirst, from mild to severe, which can ease before the body has made up all the fluid it lost; dry lips and tongue; slower thinking and poorer work; passing less urine, or darker urine. | Drink water. Skip caffeine, fizzy drinks, alcohol and salt tablets. Loosen tight clothing and take off clothing that isn’t needed, PPE included. When the heat or the dehydration is extreme, replace electrolytes. |
| Heat rash | Small, raised, red spots that itch, on the face, neck, back, chest or thighs. | Get the worker somewhere cooler and less humid. Keep the rash dry, take off clothing that isn’t needed (PPE included), and put on a cold compress. |
| Heat cramps | Painful, often incapacitating cramps in muscles, especially during demanding physical work. | Stop, and rest quietly in a cool place until recovered. Give an electrolyte solution. |
| Fainting | Heat syncope can happen while standing or rising from sitting. | Lay the worker down flat straight away, with the legs a little raised and the head not raised, then treat it as heat stroke. |
No stop-work temperature, and why
Safe Work Australia says there is no maximum temperature at which workers are required to stop, because a single figure cannot account for humidity, air flow, how hard and how long people work, and whether they are fit and used to the heat. Instead, the business must eliminate or minimise the risk so far as is reasonably practicable, which may mean cancelling or rescheduling work until it is cooler.
Heat-related illness happens when the body can no longer hold a healthy temperature. It is progressive and can be life threatening, and training people to recognise the early signs helps first aid start promptly. A worker on medication, with a medical condition, or who has had heat illness before is more susceptible, and the business should alert them and watch them closely, so far as is reasonably practicable.
Planning a pour around the heat
On a pour, the heat belongs in the plan. Queensland’s concrete pumping code asks the site to set a realistic time schedule before a major pour, with an allowance for weather among other things. Safe Work Australia’s order of controls, applied to the day:
Eliminate
Its first example is cancelling outdoor work when temperatures are high.
Substitute, isolate, engineer
Swap physical work for work a machine can do, keep people away from hot machinery, and set up shade tents.
Administrative controls
Training, instruction and supervision, and scheduling physically demanding work for the cooler parts of the day.
Protective equipment
Breathable, light clothing for any risk that remains.
Review
Check the controls are working as planned.
A heatwave is when the maximum and minimum temperatures are unusually hot over at least three days. Safe Work Australia says warmer nights mean poorer sleep, heat starts earlier and lasts longer, and fatigue affects people’s ability to work safely. It asks for more risk assessment, work in cooler parts of the day, less physical effort, cool fresh water, shade or air-conditioning where possible, nobody working alone where possible, and work planned so people can set their own pace.
A health and safety representative who has completed their training can direct a worker in their group to stop unsafe work, if they reasonably believe there is a serious risk from an immediate or imminent hazard and have consulted first, unless the risk is too immediate to allow it.
32ºC: the line for a house slab
For a house slab built to the NCC’s Housing Provisions outside South Australia, the NCC 2025 says: “Concrete must not be poured if the air temperature on site exceeds 32ºC unless written instructions from a Professional Engineer are followed.” The same clause’s explanatory note says the truck should be fully discharged within one and a half hours of the concrete first being mixed with water, unless a suitable retarder has been specified.
So heat bears on a pour for two reasons at once: the people placing it, and the concrete. The NCC’s concrete clause, line by line.
Where to check Safe Work Australia’s working in heat pages, and the regulator for your state or territory, listed on Safe Work Australia’s regulator contacts page.