Across Australia, summers are getting hotter, heatwaves are more frequent, and workplaces are feeling it. In 2024 the world recorded its hottest year on record, and new UN guidance released in August 2025 now classifies occupational heat stress as a major global hazard, not a niche OH&S issue. (World Meteorological Organization+1)
For Australian employers, that has very real implications: heat and dehydration don’t just make people uncomfortable - they reduce productivity, increase injuries, and raise WHS risk. A simple, practical control is also one of the most overlooked: reliable access to cool, palatable drinking water in every workplace.
In this article we pulled together up-to-date research, including new 2024–2025 evidence, to show why investing in hydration (for example, a plumbed filtration unit or bottled water cooler system) is now part of good governance, not just staff perks.
1. What the latest research says about hydration and brain performance
Over the last few years, several large studies have moved the hydration conversation away from “drink eight glasses” and towards measurable changes in thinking, reaction time and decision-making.
Recent peer-reviewed work has found:
- A 2024 analysis of a large US adult cohort showed that everyday “ad libitum” dehydration (people just drinking what they feel like) is associated with poorer performance on cognitive tasks, even outside extreme heat or exercise settings. (PMC)
- A 2023 study in BMC Medicine following adults over two years found that both under-hydration and over-hydration were linked to faster decline in global cognitive function scores, suggesting hydration status is a meaningful long-term brain health factor. (BioMed Central)
- A 2024 study of middle-aged and older adults (Health and Retirement Study) reported that suboptimal hydration was associated with weaker executive function -the mental skills we rely on for planning, focus and complex tasks. (PubMed)
- In 2025, a Scientific Reports paper reported that repeated episodes of high serum osmolality (a blood marker of chronic under-hydration) were linked with higher odds of low cognitive screening scores, indicating persistent under-hydration may quietly erode everyday mental performance. (SafeWork NSW)
Recent reviews now conclude that even mild dehydration (1–2% body mass loss) can impair attention, working memory and reaction time -exactly the functions modern workers need in offices, warehouses, call centres and on the road. (Nature)
For employers, this means that “just a bit thirsty” is no longer trivial - it’s a measurable performance drag.
2. Heat, dehydration and workplace injuries
The clearest data on workplace risk is now coming from heat-exposed workers, and it’s sobering.
- A 2025 nationwide analysis of more than 845,000 US occupational injuries found a clear dose–response relationship between heat and injury risk: compared with a day at 27°C (80°F), the odds of injury were about 10% higher at 38°C (100°F), and 20% higher at 43°C (110°F). (BioMed Central)
- The same study estimated that around 28,000 workplace injuries in 2023 were attributable to heat alone - and noted that this is likely an under-estimate because many heat-related injuries are never labelled as such.
Global agencies are now joining the dots:
- The World Health Organization (WHO) and World Meteorological Organization (WMO) reported in August 2025 that worker productivity decreases by 2–3% for every degree above 20°C (measured as heat stress, not just air temperature). (World Health Organization+1)
- Their joint guidance estimates that over 2.4 billion workers - around 70% of the global workforce - are exposed to excessive heat, leading to more than 22.8 million occupational injuries each year.
While these are global numbers, the mechanism is simple and universal: as people get hot and under-hydrated, their vigilance, balance and motor coordination drop, making mistakes and incidents more likely.
3. Australian evidence: our workers are adapting to heat, but hydration is the weak link
Closer to home, Australian research is starting to unpack what this means on the ground:
- A 2024 study led by The University of Western Australia tracked mine service workers over 14-day swings in harsh conditions across different seasons. It found that cognitive performance stayed relatively stable as workers adapted to heat, but dehydration remained a “key issue”, with workers showing greater dehydration and sweating in summer despite similar workloads. (The University of Western Australia)
- The authors concluded that targeted interventions - like structured hydration breaks and easier access to fluids - are needed to maintain health and safety as conditions get hotter.
In other words: Australian workers can adapt to heat to a point, but they are not naturally drinking enough to stay safely hydrated without organisational support.
4. Are adults drinking enough? Australian guidelines vs reality
The Australian Nutrient Reference Values (NHMRC) recommend that, on average:
- Adult men consume about 2.6 L/day of fluid (around 10 cups)
- Adult women consume about 2.1 L/day of fluid (around 8 cups)
These figures are higher again for people who are physically active or working in very hot environments. (Eat For Health+1)
Yet workplace health providers summarising Australian survey data suggest that many adults are falling short, with typical intakes closer to ~1.3 L/day, substantially below guidelines. (Employ Health+1)
Public health resources like Victoria’s Better Health Channel clearly outline the consequences: headache, lethargy, slowed responses, mood changes and confusion are all recognised symptoms of dehydration - long before we get to medical emergencies like heat stroke. (Better Health Channel)
In a workplace context, those symptoms look a lot like:
- Slower call handling times
- More errors in orders and data
- Fatigue-related near-misses in driving or forklift operations
- “Foggy” thinking during complex tasks
5. What about office and indoor workers?
It’s easy to assume hydration is only a concern for outdoor or heavy manual labour. The evidence says otherwise:
- The 2025 Greek working population study in Nutrients found that a large proportion of employees across varied roles (not just outdoor work) started the day already mildly dehydrated, and those with poorer hydration reported more fatigue and worse perceived cognitive performance.
- Reviews of hydration and cognition show similar effects in office-style tasks, such as attention, working memory and simple problem-solving.
In climate-controlled offices, people may not feel as thirsty, but air-conditioning increases insensible fluid loss. Coffee, tea and soft drinks contribute some fluid, but also caffeine and sugar. Tap water from a bathroom or kitchen sink in an older building often isn’t appealing - so people delay drinking, or default to sugary beverages instead.
A well-located water cooler with cool, palatable water changes that friction: it makes “a quick glass of water” the easiest option.
6. Do workplace hydration programs actually work?
A key question for any business is: if we invest in hydration, will it actually change behaviour?
Evidence from intervention studies say yes:
- A workplace water-intake program introduced across several worksites -including education sessions, easy access to water and prompts to drink regularly -significantly increased average daily water intake and reduced self-reported fatigue and headaches among employees over several months. (PMC)
- Other trials have shown that simply improving access to appealing drinking water (for example via dispensers or coolers) leads to meaningful increases in water consumption and decreases in sugar-sweetened drink purchases. (ResearchGate)
While not all of these studies are Australian, the principles are universal: make water visible, convenient and pleasant to drink, and people drink more of it.
7. What Australian WHS regulators say about drinking water
Australian WHS obligations already recognise hydration as a basic requirement:
- Safe Work Australia’s guidance on managing the risks of working in heat explicitly states that PCBUs (Person Conducting Business or Undertaking) must ensure workers have access to cool drinking water and encourage them to stay hydrated, noting that “thirst is satisfied before fluid loss is replaced”. (safeworkaustralia.gov.au)
- SafeWork NSW’s Code of Practice: Managing the work environment and facilities and related guidance make it clear that employers must provide clean, safe and accessible drinking water, close to where work is carried out. (SafeWork NSW+1)
In practice, that means:
- Water should be free for workers to consume
- It should be reasonably cool and palatable
- It should be readily accessible - not a long walk away or in inaccessible rooms
- It should be hygienic in delivery - that is, not from the same sink used for food preparation, handwashing or dishwashing.
For many workplaces, a properly maintained water cooler with reliable bottle or spring water delivery is the simplest way to comply, especially when:
- The building’s plumbing is old or of uncertain quality
- Staff are spread across large sheds, warehouses or yards
- Sites are remote or semi-rural, where mains water quality and taste can vary
8. Practical steps: what “good” looks like in workplace hydration
Drawing on the research and WHS guidance above, a robust workplace hydration strategy typically includes:
- Multiple water points
- Coolers located within easy reach of all work areas, not just the lunchroom.
- For outdoor or mobile teams, portable coolers or eskies with bottled water.
- Appealing, good-tasting water
- Filtered or high-quality spring water to encourage regular drinking.
- Cups or reusable bottles available so “I forgot my bottle” isn’t a barrier.
- Structured hydration breaks in heat
- Short, regular breaks during hot periods, tied to existing rest breaks and toolbox talks.
- Supervisors trained to prompt drinking and recognise early dehydration symptoms.
- Clear messaging and culture
- Toolbox talks and posters linking hydration to safety and performance, not just comfort.
- Normalising water as the default drink instead of soft drink.
- Maintenance and reliability
- Regular servicing and cleaning of coolers.
- Reliable delivery or supply so water never “runs out by lunchtime”.
9. How Summer Springs supports safer, more hydrated workplaces
For businesses across regional NSW, especially in hotter inland areas, bottle-fed spring water coolers offer a simple, scalable way to improve hydration:
- Consistent access to cool, great-tasting water encourages staff to drink more, more often.
- Visible hydration points remind staff to top up between tasks.
- Regular scheduled deliveries mean operations don’t depend on ad-hoc supermarket runs or staff bringing water from home.
When combined with heat-management policies and WHS training, a well-designed hydration approach doesn’t just tick a compliance box - it can help protect staff health, support cognitive performance, and reduce the risk of heat-related errors and injuries.
If you’d like to review your workplace hydration setup - from office coolers to warehouse and remote-site solutions - the Summer Springs team can help design a practical plan suited to your site, roster and risk profile.
If you’d like to discuss how we can help, call 1300 654 001.
Key research cited
- Rosinger AY et al. (2024). Ad libitum dehydration is associated with poorer performance on cognitive tasks.PMC
- Nishi H et al. (2023). Hydration status and longitudinal cognitive decline. BMC Medicine. BioMed Central
- Singer MR et al. (2024). Associations between hydration status and executive function in middle-aged and older adults. PubMed
- Nishikawa T et al. (2025). Repeated elevated serum osmolality and cognitive performance. Scientific Reports. SafeWork NSW
- Alahmad B et al. (2025). A nationwide analysis of heat and workplace injuries. Environmental Health. BioMed Central
- WHO / WMO (2025). Climate change and workplace heat stress + WHO Q&A Workplace heat stress. World Health Organization+1
- Taggart S et al. (2024). Mine workers adapt to heat across seasons but dehydration a concern. UWA / Applied Ergonomics. The University of Western Australia
- NHMRC / Australian Government: Nutrient Reference Values -Water (Eat For Health). Eat For Health
- Better Health Channel (Vic Govt): Water -a vital nutrient. Better Health Channel
- Safe Work Australia: Managing the risks of working in heat. safeworkaustralia.gov.au
- SafeWork NSW: Facilities at Work / Managing the work environment and facilities. SafeWork NSW+1
- Papadopoulou et al. (2025). Hydration habits and water balance in a working population. Nutrients. MDPI
- Luo et al. (2022). Effectiveness of a workplace drinking water intervention on employees’ water intake. PMC+1
