Heat stress happens when your body takes on heat faster than it can get rid of it. In Queensland it is a real risk for anyone working outdoors, in roof spaces, kitchens, workshops or near hot plant, and it can get worse quickly. At its worst, heat stroke, it can kill. There is no temperature in Queensland law at which work must stop. Instead, a business must manage heat like any other work health and safety risk, and every worker needs to know the warning signs and what to do.
What is heat stress?
Your body cools itself mainly by sweating. When the sweat evaporates from your skin, it takes heat with it. Heat stress is the load on your body when that cooling cannot keep up, because of the weather, the work, or what you are wearing. If the load keeps building, your core temperature climbs and you develop heat illness, which ranges from heat rash and cramps through to heat exhaustion and heat stroke.
Queensland’s approved Managing the Work Environment and Facilities Code of Practice 2021 notes that heat-related illness can come from high air temperatures, high radiant heat or high humidity, and that it is potentially fatal.
What raises the risk?
It is not just the temperature on the forecast. The code of practice says to look at both the environment and the person.
- The environment: air temperature, humidity (on humid days sweat cannot evaporate as easily), air movement, and radiant heat from the sun, hot surfaces or plant.
- The work: how physically hard it is, how long it goes for, and clothing or PPE that traps heat, such as coveralls, respirators and chemical suits.
- The person: some prescription medicines, age, health conditions, pregnancy and breastfeeding, fitness, and whether they are used to working in the heat. New starters and people back from leave are at higher risk. Safe Work Australia also notes that someone who has had heat illness before is more susceptible.
Signs of heat illness
The code of practice says to give immediate help if any worker has dizziness, fatigue, headache, nausea, breathlessness, clammy skin or difficulty staying alert. The main types of heat illness, from mild to life-threatening, are:
- Heat rash: an itchy rash of small red spots, caused by heavy sweating.
- Heat cramps: painful muscle cramps or spasms, usually in the legs or stomach, during or after hard, sweaty work.
- Fainting (heat syncope): can happen while standing, or when getting up from sitting.
- Heat exhaustion: heavy sweating with pale skin, dizziness or fainting, weakness or tiredness, headache, nausea or vomiting, and a fast, weak pulse. It can turn into heat stroke if it is not treated.
- Heat stroke: a medical emergency. Look for confusion, slurred speech or poor coordination, odd behaviour, a seizure, collapse or unconsciousness. The skin is hot but may be dry or still sweaty, so do not wait for someone to stop sweating. Body temperature is usually above about 40°C.
If someone is confused or not making sense in the heat, treat it as heat stroke and call triple zero (000).
First aid for heat illness
This is general information and does not replace first aid training. Follow your first aider and the triple zero operator.
Heat exhaustion
- Stop work and move the person somewhere cool, in shade or air-conditioning, and have them lie down.
- Take off their hard hat and any extra PPE, and loosen tight clothing.
- Cool them with wet cloths or cool water on the skin, and fan them.
- Give small sips of cool water, but only if they are fully alert and able to swallow.
- Stay with them. Call 000 if they vomit, pass out, get worse, or are not better within about 10 minutes.
Heat stroke
- Call 000 straight away, then start cooling. Do not wait for the ambulance to start.
- The fastest way to cool someone is cold water immersion up to the neck, if it is available.
- Otherwise, soak them with cold water and fan them hard, and put ice or cold packs on the neck, armpits and groin.
- Only give a drink if they are fully conscious and able to swallow.
- If they are unresponsive, put them in the recovery position. If they are not breathing normally, start CPR.
- Keep cooling until the ambulance arrives, or until they start to shiver.
Our guide to heat stroke in the workplace goes into more detail.
How to prevent heat stress at work
Work through the hierarchy of controls. The code of practice lists these ways to remove or reduce exposure to heat first:
- increase air movement with fans, and use air-conditioning or evaporative coolers to lower the air temperature;
- insulate hot plant, pipes and walls, and remove heated air or steam from hot processes with local exhaust ventilation;
- use mechanical aids so there is less physical effort; and
- change work schedules so the heavy work is done at cooler times, such as early morning or late afternoon.
The code then lists measures that help but are least effective if used on their own:
- slowing the pace of work;
- a supply of cool drinking water;
- a cool, well-ventilated rest area, and letting workers choose when they take breaks;
- letting people who are not used to the heat acclimatise, for example with job rotation and regular rest breaks;
- light clothing that lets air move and sweat evaporate; and
- training on the hazards of working in heat and how to recognise and act on the symptoms of heat-related illness.
A few more practical points:
- Drink small amounts often. Start the shift hydrated and do not wait until you are thirsty. Our guide to keeping hydrated at work covers how much, electrolytes and what the law says about drinking water.
- Build up to the heat. Acclimatisation usually takes one to two weeks of gradually increasing time and effort in the heat, and it is partly lost after time away. Safe Work Australia warns it is not a reliable control on its own.
- Check the forecast. The Bureau of Meteorology’s heatwave service runs from October to March, and Workplace Health and Safety Queensland has a free heat stress (basic) calculator as a first step in assessing the risk.
- Use a buddy system. Workers watch each other for early signs, and anyone working alone needs a way to check in.
- Protect skin from the sun. A brim or hard hat brim and neck flap, a long-sleeved collared shirt, sunglasses and sunscreen. See our sun safety tips.
What does Queensland law say about working in heat?
- The general duty. A person conducting a business or undertaking (PCBU) must ensure, so far as is reasonably practicable, the health and safety of workers, including a work environment without risks to health and safety (section 19 of the Work Health and Safety Act 2011 (Qld)).
- Extremes of heat. A PCBU must ensure, so far as is reasonably practicable, that workers carrying out work in extremes of heat or cold are able to carry out the work without risk to their health and safety (section 40 of the Work Health and Safety Regulation 2011 (Qld)).
- Drinking water. A PCBU must ensure, so far as is reasonably practicable, adequate facilities for workers, including drinking water (section 41 of the Regulation). The code of practice says drinking water must be free, easy to get to, close to hot or strenuous work, and should be at or below 24°C. On a construction project, the principal contractor must make sure an adequate supply of potable, clean and cool drinking water, and a sheltered area for meals and breaks, is reasonably available to each construction person (section 315A and schedule 5A).
- No stop-work temperature. Workplace Health and Safety Queensland says there is no workplace exposure standard or limit for heat stress. Any temperature trigger you see is a workplace, industry or project policy, not the law.
- SWMS. Construction work in an area with artificial extremes of temperature is high risk construction work and needs a safe work method statement (sections 291 and 299 of the Regulation).
- Workers’ duties and rights. Workers must take reasonable care for their own and others’ health and safety and follow reasonable instructions (section 28 of the Act). A worker may stop work if they have a reasonable concern that it would expose them to a serious risk from an immediate or imminent hazard (section 84).
- Notifiable incidents. A heat illness that needs immediate treatment as an in-patient in a hospital is a serious illness, and the business must notify Workplace Health and Safety Queensland immediately (sections 35, 36 and 38 of the Act). See our guide to notifiable incidents in Queensland.
First aid equipment and trained first aiders, or access to them, are also required (section 42 of the Regulation), and your emergency plan should cover heat stroke. Our guide to workplace first aid requirements has the details.
Templates to help you manage heat
Our heat stress policy template sets out how to assess heat, provide water and shade, bring workers up to the heat and respond to heat illness. For the work itself, the heat stress and working outdoors SWMS covers the job step by step, and the hot weather and hydration toolbox talk is ready to run with your crew before the hot weather hits. Pair them with the free poster above.
Frequently asked questions
How do you prevent heat stress at work?
Remove or reduce exposure first: fans or air-conditioning, insulating hot plant, mechanical aids and moving heavy work to cooler times of the day. Then add cool drinking water close to the work, a cool rest area, regular breaks, light clothing, a gradual build-up for new and returning workers, and training so everyone knows the warning signs. Drink small amounts often and don't wait until you are thirsty.
What are the signs of heat stress?
Early signs include dizziness, tiredness, headache, nausea, breathlessness, clammy skin, muscle cramps and difficulty staying alert. Heat exhaustion adds heavy sweating, pale skin, vomiting and a fast, weak pulse. Confusion, slurred speech, collapse or a seizure means heat stroke: call 000 and start cooling the person straight away.
At what temperature should work stop in hot weather?
There is no set temperature in Queensland law. A business must make sure, so far as is reasonably practicable, that workers doing work in extremes of heat or cold can do it without risk to their health and safety (section 40 of the Work Health and Safety Regulation 2011 (Qld)). What that takes depends on the job, the conditions and the people, and it can include cooling, work at cooler times, rest breaks and training. Any stop-work temperature you see quoted is a workplace, industry or project policy, not a legal rule.
Does my employer have to provide drinking water and shade?
A business must ensure, so far as is reasonably practicable, adequate facilities for workers, including drinking water (section 41 of the Work Health and Safety Regulation 2011 (Qld)). The approved Managing the Work Environment and Facilities Code of Practice 2021 says drinking water must be free and should be at or below 24 degrees Celsius. On a construction project, the principal contractor must also make a sheltered area for meals and breaks, and an adequate supply of clean, cool drinking water, reasonably available to each construction person (section 315A and schedule 5A).
Is heat illness a notifiable incident?
It can be. An illness that needs the person to have immediate treatment as an in-patient in a hospital is a serious illness, and a serious illness is a notifiable incident that the business must notify to Workplace Health and Safety Queensland immediately (sections 35, 36 and 38 of the Work Health and Safety Act 2011 (Qld)).
Should workers use electrolyte drinks?
Water comes first. When workers are sweating heavily, Workplace Health and Safety Queensland recommends replacing electrolytes as well, for example with an electrolyte or sports drink. Use them as well as water, not instead of it, and check with a doctor first if you are on a low-salt diet or have a heart or kidney condition.
This is general information, not legal or medical advice. Check the current law or talk to Workplace Health and Safety Queensland for your situation, and follow first aid training and triple zero (000) instructions in an emergency.
This Post Is Part Of A Series: 101 Toolbox Topic Ideas For The Construction Industry
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Templates for this job
Ready-to-edit Word and Excel templates for Queensland workplaces.
