Heat Stress - Signs, Symptoms and Protocols for Workplace Health and Safety Management
Working in the Australian heat can be hazardous and is a common cause of harm among Australian workers. Known for its extreme heat, dryness and damaging levels of ultraviolet radiation for most of the year, workers are more susceptible to developing heat-related illnesses. One qualitative study in South Australia found that 30% of outdoor workers had experienced heat-related injuries, and only 20% of the employees surveyed stated that their work would cease when the ambient temperature exceeded 40°C (1).
Heat stress is more than simply feeling a little sweaty and uncomfortable - not everyone reacts to heat in the same way.
Heat-related illnesses can be fatal if prompt medical attention is not sought, especially in cases of heat stroke, occurring when your body absorbs more heat from your environment than you can physically get rid of through perspiration or other cooling mechanisms (2). This group of medical conditions can range in severity, from more mild reactions such as heat rash and heat cramps, to dizziness and fainting, and heat exhaustion. Heat stroke is the most severe form of heat-related illness, and is a medical emergency (3).
Heat stroke occurs when the body’s core temperature reaches above 40.5 degrees C., well exceeding the ideal core temperature of around 37 degrees C. Our organs are not designed to function at high temperatures and can suffer damage if the core body temperature is not lowered quickly (3). Sequelae of heat stroke include central nervous system changes such as delirium, coma and seizures, and the liver, kidneys, muscles and heart are particularly susceptible to damage via heat stroke. Delayed treatment can even result in death (3).
Further, not everyone reacts to heat stress in the same way. Our general health, age, weight, medication use, and specific medical conditions influence the ways in which our body responds to heat. People with high blood pressure, heart and or respiratory disease, or people who are pregnant are disproportionately affected by heat and may need to take special precautions (4). Given that 11% of Australians have high blood pressure (5) and 1.2 million more have heart disease (6), and with incidence rates of these conditions rising, increasingly more workers will be at risk of heat stress.
Environmental factors can also contribute to the risk of heat-related illness. Exposure to direct sunlight without shade relief, strenuous tasks or work requirements for sustained periods, exposure to reflected heat from construction materials, polished aluminium and glass, heat build-up in roads and concrete structures, or additional heat exposure from machinery are such examples (2). Everyone in the workplace has a duty of care to ensure their own and their colleagues' safety. Employers must ensure that their employees are safe on the job and that health and safety risks are minimised. However, environmental heat is not always able to be controlled. As such, adequate personal protective equipment, facilities and allowances such as regular water breaks must be available to ensure workers' safety (7). This also includes providing first aid supplies and training for employees should heat-related illnesses strike.
While the Safe Work Australia guidelines for personal protection from the sun are clear, they are not always put into practise.
A May 2016 Safe Work Australia study that surveyed 459 construction workers found that solar UV radiation is the most common carcinogen to which this population was exposed. While 86% of these workers were exposed to UV solar radiation, only 8% of those who spend more than four hours a day outside use all four major controls for preventing solar UV radiation exposure, which is sunscreen application, wearing a hat and clothes that cover the arms and legs, and working in the shade (2). Further, a 2016 Skin Health Australia Report found that 65% of workers say their employers don’t provide clothing to protect them from the sun and 74% aren’t provided with sunglasses to protect their eyes (2).
The Work Health and Safety (WHS) laws do not specify a ‘stop work’ temperature. A single ‘stop work’ temperature would not capture the range of factors, as previously described, which make working in heat hazardous. Instead, a heat clause is included in the employment agreements in some workplaces. For workplaces that do not have this clause, the WHS Act outlines a broad duty for persons conducting business or undertaking (PCBUs) to follow the WHS laws and provide a safe work environment ‘so far as reasonably practicable’ (2).
A 2020 report by the Centre for Future Work has proposed that the current labour protections, including health and safety laws, are inadequate, and has pointed to a profit-driven culture of safety complacency within the industry. Accounts from those who work in heat say that WHS policies might appear to offer protection, but in practice, it is simply not the case. Further, employers do not want work to stop even when heat stress risk is very high, and employers prioritise productivity over worker health and safety.
Dr Elizabeth Humphrys, an associate at the Australia Institute’s Centre for Future Work and co-author of the Heat Stress in the Era of Climate Change report, explained that “[2019’s] devastating Black Summer bushfires highlighted that for many workers across Australia, appropriate policies and plans are not always in place to ensure that they are protected from dangerous heat stress-related conditions that could cause illness or injury to themselves or others.” Dr Humphrys also asserted that climate change is contributing to the growing problem of heat stress in a wide range of Australian workplaces. She explained that “[their] research shows that current workplace conditions are woefully inadequate, while climate change will only serve to make conditions worse. To protect workers and the wider community, not only must policymakers act to mitigate the impacts of heat stress, but they must also act on the causes of the climate heating, itself.” (8)
Until such wide-scale industry changes are made, workers should be aware of both the risks of heat-related illnesses and the appropriate first aid if an injury occurs, to prevent long-term heat-related harm to themselves and their colleagues.
First aid for dehydration includes fluid replacement, rest, loosening or removing tight or unnecessary clothing, and avoiding caffeinated, carbonated and alcoholic drinks, and salt tablets. For heat rash or heat cramps, move the worker into a cooler environment to rest until symptoms resolve. Fainting can occur from a sitting or standing position, but it’s important to lie the worker flat with legs elevated if possible and monitor for return of consciousness.
First aid for heat stroke is more involved, however. As heat stroke is a medical emergency, 000 must be called as soon as possible. Monitor the worker for signs of loss of consciousness or seizures, and aim to reduce the worker’s temperature via cool fluids, air-conditioned spaces, cold compresses or cold baths if available. Do not attempt to give oral fluid if the worker is not fully conscious (9). While heat stroke is the least common of all heat-related illnesses, it is still crucial to remain vigilant for the signs and symptoms and provide first aid as soon as possible. In the meantime, legislative changes must be enacted and PBCUs must uphold their responsibilities to ensure their workers' safety on the job.
Xiang, J., Hansen, A. and Pisaniello, D. (2016) ‘Workers’ perceptions of climate change-related extreme heat exposure in South Australia: A cross-sectional survey’, BMC Public Health, vol 11, no 16, p. 549. https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-016-3241-4