With parts of the country experiencing the hottest spring on record, finding ways to reduce the risk of heat stress should be high on everyone’s safety agenda as we head into summer.
Lead researcher on the Working in the Heat study at the Australian National University Dr Liz Hanna has found that the ambient temperature is not the only issue – so is humidity.
Dr Hanna says that just as there are clauses in a construction contract that cover stopping work due to rain, there should also be clauses that cover halting due to high humidity levels of 70 per cent or above. Her research showed that at these extreme levels of humidity, the body’s natural cooling process – perspiration – simply does not work.
Her research showed that at these extreme levels of humidity, the body’s natural cooling process – perspiration – simply does not work.
In terms of ambient temperature, in South Australia and Victoria, workers on union-affiliated sites can down tools when the mercury hits 35 degrees Celsius. However, in other states, there are no such provisions. In the 2016 Coronial inquest into the death of Glen Newport at Roma in Queensland, the Coroner concluded that heat stress was the cause of death.
A number of recommendations were made including that the heavy construction industry “devise and implement an industry-wide code of practice in relation to the prevention and management of heat injury in the course of work.” Further, he recommended there be an ultimate cut-off temperature that signals work must cease. When dangerous heat is expected, programs should also make provision for work to be carried out in at night as it is cooler then.
The Defence Department’s policy on mitigating heat injury was cited in the inquest. This policy was developed following the death of a soldier in the Northern Territory as a result of heat stress.
The resulting health directive states that when someone becomes distressed in the heat, the goal is to get their temperature down to below 38 degrees within 20 minutes, as a core temperature of above 39 degrees indicates heat stroke, and between 38 and 39 indicates a heat casualty. Methods used to reduce the person’s temperature include rehydration, using fans and cooling water sprays, and reducing the level of clothing.
Methods used to reduce the person’s temperature include rehydration, using fans and cooling water sprays, and reducing the level of clothing.
The Queensland branch of the Construction Forestry Mining and Energy Union [CFMEU] has developed its own heat stress policy based on the coroner’s recommendations. The policy sets 35 degrees as the maximum temperature for working in direct sunlight, and based on Dr Hanna’s findings, a stop work threshold of 28 degrees and 75 percent humidity for humid days. The union also issues heat alert warnings when a major heatwave, like the record-breaking one just last month, is due to hit.
Master Builders Australia’s Queensland division has some valuable tips for managing extreme heat.
The first point made is that contractors and staff need to sit down and discuss how the risks associated with hot conditions can be alleviated or mitigated. Strategies include rotating jobs in and out of the sun during peak sun exposure times, generally between 10am and 2pm.
Ceiling spaces should be avoided during the middle of the day, as they can be much hotter than the outside ambient temperature. Site amenities sheds should have working air-conditioning, and other shaded areas should be created for rest breaks, by using tarpaulins or umbrellas.
Workers should drink something cooling and non-caffeinated like water or a sports drink every 15 to 20 minutes. In addition, the CFMEU says workplaces should provide water cooler points with shade over them wherever practical.
In terms of PPE, hats or hard hats should have neck flaps as these both protect from heat stress and from UV radiation. The union also recommends wearing light clothing under coveralls or other PPE garments. Wearing cooling vests or neck cooling devices is also an option.
The union also recommends wearing light clothing under coveralls or other PPE garments. Wearing cooling vests or neck cooling devices is also an option.
When workers are experiencing symptoms of heat stress, such as feeling faint, dizzy, or nauseous – it is vital to stop, take a break, rehydrate, and look at how work can be rescheduled, MBAQ says. It also recommends that when a worker becomes dehydrated, they should not go back to work until they are fully rehydrated.
Generally, the higher the temperature, the more frequent breaks should be. Safe At Work has guidelines on the frequency and duration of breaks during high temperatures. It recommends that paid breaks be 10 minutes every hour when the temperature is between 30 and 32 degrees; 20 minutes every hour at 32 degrees to 34 degrees; 30 minutes every hour at between 34 and 36 degrees; and that work should cease at 36 degrees or over.