The Importance of Heat Stress Monitoring in the Australian Summer
A Growing Risk: Extreme Heat in Australian Workplaces
Between 2006 and 2017, around 2 per cent of deaths in Australia were associated with the heat.1 With illnesses related to extreme weather conditions to be exacerbated as the number of hot days in Australia are projected to increase, this has significant implications for workplace safety. Heat poses a serious hazard in industries like manufacturing, construction, and mining, where workers frequently endure high temperatures and strenuous conditions, often in harsh outdoor environments.
Heat stress covers multiple heat-related illnesses that occur when the body is unable to cool itself enough to maintain a healthy temperature. Caused by dehydration preventing the body from sweating and overheating can lead to health conditions ranging from mild discomfort to life-threatening if the core body temperature exceeds 40.5 °C.2
Heat stress management programs are vital for the prevention and protection of workers in hot conditions. A number of factors unique to each individual such as age and condition of health also needs to be considered when conducting a heat assessment. A study by Varghese et al.3 found that those most commonly impacted are;
Males
Workers aged under 34 Years
Apprentice/trainee workers
Workers in medium and heavy strength industries
The Symptoms of Heat Stress
Heat stress symptoms range from minor to severe and may require medical intervention. Common symptoms can include:
Common Symptoms of Heat Stress
Deterioration in existing medical conditions
A common symptom and can lead to further health complications.
Heat rash
Skin irritation caused by excessive sweating
Heat cramps
Muscle pains and spasms that can occur after strenuous activity in a hot environment.
Dizziness and fainting
Caused by reduced blood flow to the brain.
Heat exhaustion
Occurs when excessive sweating in a hot environment reduces blood volume and can develop into heatstroke.
Heatstroke
Occurs when the core body temperature rises above 40.5 degrees and the body’s internal systems begin to shut down. This is a serious health issue and requires urgent medical attention.
Guidelines for Managing Heat Stress in the Workplace
In Australia, there are no specific regulations that set out the maximum temperature for working in the heat. However, a person conducting a business or undertaking (PCBU) has a general duty to manage health and safety risks (such as the hazard posed by extreme heat) by eliminating or, if elimination is not possible, minimising them so far as is reasonably practicable. Safe Work Australia provides a guide for managing the risks of working in heat that outlines occupational health and safety duties relating to working in heat and offers information for managing the risks of heat. State occupational health and safety regulators also generally provide their own guidance for working safely in heat.
Heat Stress Monitoring for Occupational Health and Safety
Monitoring is an important aspect in mitigating the risks related to working in extreme conditions and can help inform assessors on the workplace conditions. One of the easiest ways to monitor the risks is by performing a risk analysis utilising an appropriate index. The two most common indices are Thermal Work Limit (TWL) and Wet Bulb Globe Temperature (WGBT) index.
The TWL index is a measure of wet and dry bulb temperatures, wind speed and radiant heat. The purpose of the index is to predict the amount of work in the heat that can be undertaken without exceeding a safe core body temperature. Having access to the data provided by this index can help employers ensure that the conditions are safe for workers whilst maintaining work efficiency. An assessment using the index can be aided by an instrument capable of measuring the TWL indicators, such as the Scarlet Tech TWL-1S Heat Stress Monitor.
An alternative index is the WGBT index which is a measure of temperature, radiant heat and humidity. This index provides a measure for stress on the body caused by the environmental conditions. Calculating the WGBT is relatively quick and simple with an instrument capable of measuring the related variables such as the QUESTemp QT-36 Portable Heat Stress Monitors.
An analysis can be aided by available management software that can set up, manage, record and analyse the data collected by the monitors. TWILIT is a free heat stress management software provided by Scarlet Tech that works with the TWL-1S monitor and is ideal for long term monitoring of conditions. An alternative is the Detection Management Software designed by TSI to work with the QUESTemp range of data logging instruments. Both sets of software provide solid platforms for analysing the data provided on environmental conditions in the workplace.
Workplace Heat Stress Risk Management and Prevention
The best heat stress management strategy is to prevent it before it becomes an issue. There are many ways to help the body deal with heat and manage a safe core body temperature including:
Staying hydrated - fluid retention is key in managing the core body temperature and it is important to replace the fluids lost to sweating. Hydration can be through drinking plenty of water and hydration solutions, such as Aqualyte, which have been developed to replenish your body’s electrolytes.
Avoiding the heat - staying cool by remaining in the shade can be obvious but is not always practical on the work site. It is important to take regular breaks in the shade and limit physical activity where possible to give the body a chance to cool down when facing extreme conditions.
Wearing suitable clothing - when dealing with high temperatures, it is important to protect yourself by wearing lightweight clothing, and if you are working in the sun wearing lightweight clothing that covers your skin offers valuable protection.
Training and education - Ensure that workers are well educated to recognise symptoms and treat symptoms of heat stress should they arise. In an emergency, call 000 or your local doctor.
Heat stress is a serious issue that impacts many workers around Australia. Air-Met Scientific stocks a range of Heat Stress Monitoring equipment for sale and rental that can help you monitor conditions. Contact us today to find out more about the best monitoring solutions for your workplace.
References
Longden, T. Brearley, M. Quilty, S. (2021, January 26). As heatwaves become more extreme, which jobs are riskiest? Retrieved from ABC News: https://www.abc.net.au/news/2021-01-26/as-heatwaves-become-more-extreme-which-jobs-are-riskiest/13088750
NSW Health. Heat-related illness Retrieved from NSW Health: https://www.health.nsw.gov.au/environment/beattheheat/Pages/heat-related-illness.aspx
Varghese, B. Barnett, A. Hansen, A. Peng, B. Nairn, J. Rowett, S. Nitscke M, Hanson-Easey, S. Heyworth, J. Sim, M. Pisaniello, D. (2019, April 15). Characterising the impact of heatwaves on work-related injuries and illnesses in three Australian cities using a standard heatwave definition- Excess Heat Factor (EHF). Published by Springer Nature America, Inc. 2019.
