Heat Safety at Work: Hydration, Cooling and Sun Protection
Updated:
Hot conditions can affect people working outdoors, but heat is not only an outdoor-work problem. Workshops, factories, warehouses and manufacturing sites can also become high-risk environments when heat from machinery, hot processes, physical work, humidity, poor airflow or protective clothing are added together.
Managing workplace heat therefore means looking at the total heat load, not simply checking the day's maximum temperature.
Quick answer
There is no single temperature that automatically determines whether work is safe or unsafe. Heat risk depends on factors including air temperature, humidity, radiant heat, workload, airflow, clothing and PPE, acclimatisation and the individual worker. Effective heat management normally requires a combination of controls rather than relying on drinking water or one cooling product alone.
What causes heat stress at work?
Heat stress occurs when the body has difficulty getting rid of enough heat to maintain a safe internal temperature. The amount of strain placed on a worker can change considerably even when the air temperature remains the same.
| Risk factor |
Why it matters |
What to consider |
| High temperature and humidity |
Humidity can make it harder for sweat to evaporate and cool the body. |
Cooling, airflow, rest breaks and work scheduling. |
| Radiant heat |
Hot machinery, furnaces, welding processes, roofs and direct sun can add heat even when air temperature appears manageable. |
Shade, shielding, insulation and separating people from heat sources. |
| Physical workload |
Hard physical work generates additional body heat. |
Mechanical aids, task rotation, workload changes and cooler work periods. |
| Limited air movement |
Poor airflow may reduce the body's ability to lose heat. |
Ventilation, extraction, fans or mechanical cooling where suitable. |
| Clothing and PPE |
Some protective clothing, respirators and other PPE can trap heat or reduce sweat evaporation. |
Consider additional breaks, cooling and workload controls while maintaining required protection. |
| Worker factors |
Acclimatisation, fatigue, hydration, medications and some health conditions can affect heat tolerance. |
Training, monitoring, consultation and appropriate work arrangements. |
When is it too hot to work?
There is no single workplace temperature that determines whether work should automatically stop. A temperature that may be manageable during light work in a shaded, well-ventilated location could present a much greater risk when combined with high humidity, direct sun, heavy physical work or restrictive PPE.
A workplace heat assessment should therefore consider the conditions, task and workers together. Workplace Health and Safety Queensland also provides a Heat Stress Basic Calculator to help workplaces identify and assess heat-stress factors.
Conditions should also be reassessed as they change during the day. A job that is manageable early in the morning may become significantly more demanding later when temperature, humidity or radiant heat increase.
How can workplaces reduce heat risk?
Heat should be managed using the same risk-management principles as other workplace hazards. Where reasonably practicable, reduce exposure at the source before relying only on administrative measures or PPE.
Reduce heat exposure
- Move work away from hot areas where practical.
- Provide shade for outdoor tasks and rest areas.
- Insulate or shield radiant heat sources.
- Use plant, lifting equipment or mechanical aids to reduce strenuous manual work.
- Schedule demanding work for cooler parts of the day where practical.
Improve airflow and cooling
Ventilation, extraction, air conditioning, evaporative cooling and industrial fans may help reduce heat exposure depending on the workplace and process.
Fans should be treated as one part of the control strategy rather than the complete solution. Air movement also needs to be compatible with other workplace controls, particularly where dust, fumes or other airborne contaminants are present.
Browse industrial fans and ventilators.
Provide cool rest areas and suitable breaks
Workers exposed to heat should be able to recover in a cooler environment. Depending on the workplace, this may mean shade, a well-ventilated rest area or an air-conditioned space.
Work-rest arrangements may need to change as conditions, workload or PPE requirements change.
Hydration in hot workplaces
Dehydration increases the risk of heat-related illness and can affect concentration and work performance. Workers should have easy access to cool drinking water close to where work is being carried out and should be encouraged to stay hydrated throughout the shift.
Signs of dehydration can include thirst, dry lips or tongue, reduced or dark urine and reduced mental or physical performance.
Water or electrolytes?
Cool drinking water should be readily available. Electrolyte drinks can also have a role where workers are sweating heavily or where electrolytes need to be replaced. Hydration products should support, not replace, controls such as cooling, breaks, shade, task changes and heat-risk assessment.
AusTech supplies workplace hydration products including Sqwincher Hydration Sqweeze Ice Pops and other seasonal heat-management products.
Recognising heat-related illness
Workers and supervisors should understand the early signs of heat-related illness and know what action to take. Symptoms can progress from dehydration and heat cramps to heat exhaustion and potentially life-threatening heat stroke.
| Condition |
Possible signs |
Immediate response |
| Dehydration |
Thirst, dry mouth, dark or reduced urine, reduced performance. |
Move to a cooler area, rest and rehydrate. Seek medical advice if symptoms are severe or do not improve. |
| Heat cramps |
Painful muscle cramps or spasms, often during demanding physical work. |
Stop the activity, rest somewhere cool and replace fluids and electrolytes. |
| Heat exhaustion |
Heavy sweating, weakness, headache, nausea, dizziness, cramps or fainting. |
Stop work, move to a cool location, begin cooling and rehydration and monitor closely. |
| Heat stroke |
Confusion, impaired judgement, collapse, seizure, unconsciousness or other severe neurological symptoms. |
Medical emergency. Call 000 immediately and begin rapid cooling while following emergency instructions. |
Heat stroke is a medical emergency
If heat stroke is suspected, call Triple Zero (000) immediately. Move the person to a cool area and begin cooling while following instructions from emergency services. Do not attempt to give oral fluids to someone who is not fully conscious.
Heat and personal protective equipment
PPE required for another workplace hazard can sometimes increase heat load. Respirators, protective suits, welding equipment, coveralls and other equipment may restrict airflow, increase insulation or make physical work more demanding.
This does not mean required PPE should simply be removed. Instead, the heat risk should be considered alongside the hazard the PPE is controlling. Additional breaks, cooling, work rotation or scheduling changes may be needed.
For respiratory hazards, see our guide to selecting the right respirator for your work.
Sun and UV protection at work
Heat and ultraviolet radiation are related workplace issues, but they are not the same hazard. UV levels can be high on cool or cloudy days, so temperature should not be used as an indicator of UV risk.
Outdoor workers can receive substantially more UV exposure than people who work indoors. For people who regularly work outdoors, Cancer Council recommends using sun protection throughout the year because occupational UV exposure accumulates over time.
A practical sun-protection approach combines several measures:
- Slip: wear clothing that covers exposed skin while remaining suitable for the work and heat conditions.
- Slop: use SPF 50 or SPF 50+ broad-spectrum, water-resistant sunscreen. Apply before sun exposure and reapply at least every two hours, particularly after heavy sweating.
- Slap: use a broad-brimmed, bucket or legionnaire-style hat where compatible with required head protection.
- Seek: use shade and, where practical, schedule outdoor work to reduce unnecessary solar exposure.
- Slide: wear suitable close-fitting or wraparound eyewear that provides appropriate UV protection. Where safety eyewear is required, it must also be suitable for the workplace hazard.
Browse workplace sun-protection products or view safety glasses and goggles.
A practical heat-safety checklist for workshops and worksites
- Check the expected temperature, humidity and changing conditions.
- Identify radiant heat from machinery, processes, roofs, surfaces or direct sun.
- Consider the physical workload and duration of each task.
- Consider whether required PPE will increase heat load.
- Provide accessible cool drinking water.
- Provide shaded, ventilated or cooled rest areas as appropriate.
- Schedule strenuous tasks for cooler periods where practical.
- Use suitable ventilation, fans or mechanical cooling where appropriate.
- Make sure workers and supervisors can recognise heat-related illness.
- Have suitable first aid and emergency procedures in place.
- For outdoor work, include UV and sun protection in the day's controls.
Heat risk can change quickly, so controls should be reviewed when conditions, work rates, staffing, PPE or processes change.
Frequently asked questions
Is there a maximum temperature for working in Queensland?
No single ambient temperature determines whether work is safe. Workplace heat risk needs to be assessed using factors including humidity, radiant heat, workload, airflow, PPE, duration of exposure and worker factors.
Are electrolyte drinks better than water in hot workplaces?
Cool drinking water should be readily accessible. Electrolytes may also be useful where workers are sweating heavily or need electrolyte replacement. They are not a substitute for reducing heat exposure or providing suitable rest and cooling.
Can industrial fans prevent heat stress?
Fans can improve air movement and may form part of a heat-control strategy, but they should not be relied on alone. The total heat load, ventilation requirements and any dust, fume or contaminant hazards must also be considered.
Does UV exposure only matter on hot sunny days?
No. UV radiation cannot be seen or felt and can still be significant on cool or cloudy days. Outdoor workers should manage UV exposure independently of the temperature.
How often should sunscreen be reapplied at work?
Cancer Council recommends SPF 50 or SPF 50+ broad-spectrum, water-resistant sunscreen and reapplication at least every two hours when outdoors, with additional application after heavy sweating or towel-drying.
Sources and further guidance
This article has been reviewed against current guidance from:
- Workplace Health and Safety Queensland: Heat stress
- Workplace Health and Safety Queensland: Sun safety and skin cancer
- Safe Work Australia: Managing the risks of working in heat
- Safe Work Australia: First aid for heat-related illness
- Cancer Council Australia: UV radiation at work and sun protection guidance
This article provides general workplace information only. Workplace heat and UV risks should be assessed for the specific work, environment and people involved. AusTech supplies workplace equipment and consumables but does not provide WHS or medical advice.
Getting your workplace ready for hotter conditions?
AusTech supplies cooling, hydration, sun-protection and workplace safety products for workshops, manufacturing sites, maintenance teams and trade businesses. Our team can help you identify suitable product options for your application.
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