Working in heat

As the temperatures warm up around Australia, it is important for workplaces to manage the risk associated with workers in hot environments. Any industry that requires workers to work in outdoor areas exposed to radiant heat or work in confined conditions with close proximity to hot machinery needs to make sure their workers are able to carry out work without a risk to their health and safety so far as is reasonably practicable.

Air temperatures that are too high can contribute to fatigue and heat-related illnesses such as heat stress, which is potentially fatal. Heat stress occurs when the body cannot cool itself enough to maintain a healthy temperature (37°C in a grown adult). Immediate assistance should be provided if any worker experiences any of the following symptoms of heat strain: dizziness, fatigue, headache, nausea, breathlessness, clammy skin or difficulty remaining alert.

According to SafeWork Australia, both personal and environmental factors should be considered when assessing the risk to workers’ health from working in a very hot environment. Personal factors include the level of physical activity, the amount and type of clothing worn, and duration of exposure. Environmental factors include air temperature, the level of humidity, air movement and radiant heat.

SafeWork Australia says if it is not possible to eliminate exposure to extreme heat, the risk of heat strain and heat exhaustion must be minimised so far as is reasonably practicable. For example: with fans, air conditioners or evaporative coolers, insulation, local exhaust ventilation, use of mechanical aids to assist in carrying out manual tasks and alteration to work schedules so that work is done at cooler times.

Staying hydrated

During January this year, some mining sites in Western Australia reported temperatures up to 50°C or more. While these working conditions are extreme, some workers are frequently exposed to temperatures in excess of 35°C and the Bureau of Meteorology has reported there is an upward trend in the mean temperature of the hottest day of the year, increasing by around 1° over the last 100 years.

The average industrial worker reportedly sweats at a rate of over 1 L per hour working in a thermally stressful environment. This sweat contains water, and essential salts known as electrolytes. As dehydration can adversely affect worker productivity and safety, it has been suggested that a workplace heat stress management program should include a programmed drinking regime.

It is also important for workers in remote areas to have a good supply of fluids available. The human body can survive for a far longer period without food than without water. The amount required depends on body size, metabolism, climatic conditions, the food we eat and activity levels.

According to Thorzt, an electrolyte drink company, electrolyte drinks increase water retention by 25-40% compared with drinking water. The addition of other ingredients such as amino acids is also claimed to help the body to maintain stamina during prolonged physical activity. The company says the addition of amino acids to carbohydrate-electrolyte drinks has been shown to increase fluid retention 15% greater than carbohydrate-electrolyte-only drinks, and 40% greater than water.

According to details on the Thorzt Keep Hydrated Stay Productive guide, workers should avoid heavy exertion, extreme heat, sun exposure and high humidity when possible. When these cannot be avoided, take the following preventive steps:

• Monitor your physical condition and that of your co-workers for signs or symptoms of heat illnesses.
• Wear light-coloured, loose-fitting, breathable clothing such as cotton. Avoid non-breathable synthetic clothing.
• Gradually build up to heavy work. Schedule heavy work during the coolest parts of the day.
• Take more breaks when doing heavier work and in high heat and humidity. Take breaks in the shade or a cool area.
• Be aware that protective clothing or PPE may increase the risk of heat-related illnesses.

Sun protection

To protect workers from the harmful effects of the sun, workers and employers can check the daily sun protection times. The sun protection times are issued whenever the UV is due to reach 3 and above, which is the level when UV is damaging. During these times or if workers are due to be outdoors for extended periods, try to:

• reschedule work, where feasible, to minimise UV exposure by minimising outdoor work, doing outdoor jobs undercover or in the morning and late afternoon, sharing outdoor tasks and making use of shade;
• provide and enforce use of shade;
• provide and enforce use of protective clothing (long sleeves, collared t-shirts, broad-brimmed hats, hard hat attachments and sunglasses with lenses marked with appropriate UV and glare protection ratings);
• advise and remind outdoor workers to apply broad-spectrum 30+ sunscreen and re-apply every two hours. Some sunscreen is also now available in a 50+ range.