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How providing crushed ice to workers can reduce heat stress and increase productivity and safety

Crushed Ice Heat Stress

Crushed ice ingestion – commonly known as slushies – is being used successfully on mines and construction sites in the Australian tropics to reduce cases of heat stress in workers and increase productivity and safety, according to Thermal Physiologist, Matt Brearley.

Hard physical labour on hot worksites or in underground mines while wearing heat-inducing personal protective equipment (PPE) is a common scenario for many Australians – described by Brearley as industrial athletes.

Workers often suffer heat stress on these sites and may face impaired judgement and a lack of co-ordination, along with dizziness, nausea, headache and a range of other unpleasant symptoms that may also lead to a heat hangover.

Minimising heat stress among workers is an important responsibility for organisations and OHS officers in ensuring a safe workplace.

According to Brearley, author of the white paper Heat Stress in the Workplace, there have been a number of studies that have proven the effectiveness of crushed ice ingestion in minimising heat stress.

He described the studies as showing crushed ice ingestion can substantially lower core body temperatures by acting as a heat sink in the body.

Those studies began on athletes in 2003 and have also extended to military officers, firefighters and miners wearing protective clothing while working in hot conditions.

Brearley said results consistently showed that the ingestion of crushed ice is superior in lowering core body temperature than a cold drink served at 4oC, and is likely to lead to increased productivity in workers.

In a review article on crushed ice ingestion for the Journal of Military and Veterans’ Health, Brearley discussed a trial that monitored cyclists during a 40km time trial where power output was increased by 6.9% in those who had ingested crushed ice.

Another trial discussed, evaluated moderately trained runners and found they were able to run for nearly 10 minutes longer after crushed ice ingestion than those who consumed cold water – 50.2 minutes rather than 40.7.

In both studies, participants consumed around 600g of crushed ice during the 30 minutes prior to exercise.

However Brearley said that when allowing workers to self-regulate their consumption of ice, they may not consume this much, or may let the ice melt before consumption, eliminating its benefits.

He discussed evidence of this reduced consumption being found in two trials on participants in occupational settings – one on firefighters and the other miners – suggesting the “crushed ice ingestion may diminish the drive to drink” potentially manifesting in dehydration if enough fluids are not consumed.

Despite this, he concluded that crushed ice is a worthy tool for reducing heat stress in the workplace and suggested having both crushed ice and cold fluids readily available as part of a greater heat stress management strategy that includes monitoring workers.

To learn more about managing heat stress in the workplace, download the FREE Heat Stress White Paper.