Heat Stress – dehydration

Heat Stress – dehydration

Although summer in Australia has been slow in getting started, December and January promise to be very hot and humid. Now is the time to be stressing the importance of preventing heat related stresses which can be quite insidious and hit you before any signs of symptoms.

A recent article in The Department of Mines and Petroleum’s Magazine

The campaign, which runs from September to March, includes:
• regular testing of the hydration levels of workers before, during and after shifts;
• a competition for the best hydrated workforce;
• heat stress forecasts;
• promotional items; and
• regular “pitstops”.

The pitstop is run by Argyle Diamonds’ Health, Safety and Environment (HSE) team, who give an electrolyte replacement to employees on their first day back at work after rotation. According to Argyle Diamonds’ HSE Manager, Peter Firth, the station, which is located at the Argyle camp where temperatures can average about 38°C, served multiple purposes.
“It ensures hydration is the first and last thing on our workers’ minds on their first day back at work, and ensures workers are starting and finishing their shift hydrated,” he said. “It also encourages our employees to start talking about thermal stress with our team and dispels some of the myths surrounding hydration and heat.”

Heat stroke can occur without any obvious symptoms. Often victims do not sweat or feel thirsty, and they may not be aware they have heat stroke until other symptoms such as nausea and dizziness start to occur.

During the wet season and the build up to it, the average humidity can be between 67 and 72 per cent at the Argyle mine site, which is about 150 km south of Kununurra.

Rio Tinto’s campaign makes awareness of thermal stress part of the workers’ day-to-day activities.
Heat stress forecasts are included in the daily incident reports, which are communicated to teams at their pre-start meetings, and displayed in the work area or crib room.
A heat stress index barometer has also been set up outside the entry to the mine to alert workers to the day’s weather.
Hydration testing is conducted at least weekly for each work group, and monthly prizes are given to the work groups with the best hydration results. For example, one group has had 63 per cent of its members reaching excellent hydration levels while another had 50 per cent. Overall, hydration levels are continuing to improve.

Promotional items are also distributed around the site, such as bandannas, stubby holders, clip-on sunscreen bottles, and electrolyte replacement drinks in dispensers in the crib rooms and mess.
Work groups that have higher thermal stress exposure also undertake physiological monitoring, which includes monitoring heart rates, blood pressure and hydration levels at intervals throughout the work day, followed by comprehensive individual and team reports detailing the findings and recommended controls or work-rest schedules.

Peter Firth said that better awareness of the signs and symptoms of thermal stress had led to employees identifying it at the early stages.
“We have seen fewer clinical presentations of thermal stress, with decreased severity, at the site medical centre,” he said.
“We have been building a culture of interdependence with mates looking after mates. We are also training up volunteers to conduct simple hydration tests within their own work groups, to build more sustainable approach and get more buy-in from employees.”