8 Useful Things On Worker Dehydration

On the surface, dehydration and heat related illnesses make up a small fraction of worker compensation claims. In 2010-2011, they accounted for about $238,000 of a $57 billion bill. With figures like these, it’s not surprising that heat stress management isn’t exactly the cornerstone of every employer’s OHS agenda. But it should be.

You see, cases of dehydration and heat stress only become documented if the symptoms are so severe as to require medical attention, time off work and financial compensation. What these figures don’t reflect are the far more prevalent cases of ‘mild’ dehydration (classified as anywhere from 1-5% dehydration), and the increased incident rates/reduced productivity that happens as a result.

Dehydration – 8 Things Every Employer Should Know

1. Even Mild Dehydration Impacts Productivity

Just 1% dehydration has been found to decrease worker productivity by 12%. The more dehydrated the worker becomes, the further his or her physical work capacity degrades, with 3-4% dehydration bringing about a 25-50% decline in worker performance.

2. Even Mild Dehydration Effects Worker Health & Safety

At just 1% dehydration, workers begin experiencing decreased cognitive abilities, reduced concentration and alertness, and slower reaction times.

1% dehydration represents about an 800ml fluid deficit for an 80kg adult male. With average Australian industrial workers sweating anywhere from 1L to 2.5L/hr, dehydration can set in very quickly if lost fluids are not actively replaced.

3. Drugs & Alcohol Are Not The Only Form of Impairment

3% dehydration can slow your reaction time to the same extent as 0.08 Blood Alcohol Content (BAC). At 0.08 BAC you are 5 times more likely to crash your car, which begs the question – how much more likely are you to have a workplace accident when dehydrated?

As part of an innovative and award winning safety program, Leighton Contractors at the Australia Pacific LNG Project recognised that ‘fitness for work’ means not only drug and alcohol compliance, but also hydration compliance. Safety managers conduct spot hydration testing to monitor employee hydration levels. If a worker fails the test the shift supervisor is notified and he or she must cease working immediately and commence drinking small amounts frequently for one hour at which point they are re-tested. Read more about Leighton’s Heat Stress Management Program Here

4. 60% of Australian Workers Show Up Unfit For Work

Studies of Australian mine sites have found that 60% of workers report to work insufficiently hydrated for working in hot conditions (Click to Tweet), with over half found to be at least 2% dehydrated. Once dehydrated, the situation usually deteriorates throughout the day with workers typically replacing only half of the fluid they lose through sweat.

5. Educated Workers Do Not Become Dehydrated

Studies have found that workers who are educated on the importance of hydration and engage in program drinking (as opposed to drinking ad lib) report for work hydrated and maintain this status for the duration of their shifts.

Similar results are currently being achieved by Leighton Contractors at the Australia Pacific LNG Project. Leighton’s provide hydration training programs, toolbox talks, testing, and fluid consumption guidelines as part of their award winning heat stress management program. They have not had a single heat stress related incident since commencing the program in July 2012.

6. Workers Cannot Keep Hydrated by Drinking Water Alone

When we sweat we not only lose water but also essential salts and minerals known as electrolytes. Electrolytes play a number of key roles in the body, and one of these is water retention. If lost electrolytes are not replaced, a phenomena known as ‘involuntary dehydration‘ can occur, whereby the body struggles to rehydrate even when fluid intake exceeds sweat rate.

Drink an Electrolyte Drink to Replace Salts and Minerals Lost through Heavy Sweating

At Leighton’s LNG site, workers consume THORZT electrolyte drink alongside water, to replace lost solutes and maintain the correct fluid:electrolyte balance necessary for optimal health and performance.

7. Dehydration & Heat Stress Are Two Sides Of The Same Coin

Our body’s core temperature is about 37ºC. When external temperatures are below our core temperature, we lose heat via radiation (the movement of heat energy from a warmer to a colder object). When external temperatures rise above our core temperature, radiation cannot work and the body relies solely on evaporation to expel excess heat. To do this it produces sweat which evaporates from the surface of the skin, cooling surface blood cells. The cooled blood then returns to the bodys’ core, lowering our core body temperature.

If we fail to replace the fluids lost through sweat, the body must borrow water from our vital organs. This puts them under strain and causes many of the symptoms associated with dehydration. As dehydration worsens, the body has insufficient fluid to produce the amount of sweat required to cool itself and the core temperature rises. This in turn results in the onset of heat related illnesses such as heat stress, fatigue and heat stroke.

8. Workplace Risk Rises With Temperatures

A North American study examined the correlation between rising temperatures and accident rates. It found that the rate of workplace incidents rose dramatically in hotter summer months, with a rise in temperature from 20ºC to 24ºC corresponding with a 30% increase in workplace accidents.

Similarly, a recent performance study by NASA examined the effect of ambient temperature on the error rates of telegraph key operators. The results were as follows:


Temperature Mistakes in first hour Mistakes over 3 hours
27ºC 5 19
32ºC 9 27
35ºC 60 138


The elevated risk associated with these high temperatures pervades Australian work sites all year round, with workers frequently exposed to temperatures in excess of 35ºC. For those working in the Northern Territory, and northern parts of WA and QLD, it’s an every day reality – regardless of time of year.

The Hidden Costs of Dehydration to Australian Employers

The question we must ask ourselves when calculating the costs of dehydration and heat stress is not just how many workers actually fell ill, but also how many incidents and injuries could have been prevented had workers been hydrated, alert and performing at their peak?

Would that worker have caught his or her hand in that machine or been hit by that moving object had they been paying attention or been able to react faster? How much more productive could workers have been if they were alert and energetic instead of heat stressed and fatigued?

For an example of one Australian company that has recognised this issue and insight into the measures they took to set their workforce right, check out our article on Leighton Contractor’s Award Winning Heat Stress Management Program.

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It only takes 1% of dehydration to result in lowered productivity! Most of us think of dehydration as a summer problem. The days are longer