According to the latest report by the World Health Organisation and the World Meteorological Society:
- The frequency and intensity of extreme heat events have risen sharply, increasing risks for both outdoor and indoor workers.
- Worker productivity drops by 2–3% for every degree above 20°C.o
- Health risks include heatstroke, dehydration, kidney dysfunction, and neurological disorders, all of which hinder long-term health and economic security.
- Approximately half the global population suffers adverse consequences of high temperatures.
-World Meteorological Society, Aug 2025
Both the WHO and the WMO are now calling on countries and employers to consider heat stress in all occupations with emphasis on training health professionals, employers and workers to recognise the signs and pay particular attention to older adults, those with chronic illnesses and disabilities and those on low incomes. Their recommendations include the following:
· Developing occupational heat health policies in collaboration with employers, workers, health professionals and local authorities so that plans suit local conditions
· Special emphasis on affordable, scaleable solutions and environmentally sustainable solutions like real-time heat monitoring, wearable cooling devices, and passive building adaptations.
· Education and Awareness Raising
· Strong focus on Vulnerable Populations ·
· Research & Monitoring to strengthen data collection, to track effectiveness and adapt strategies over time.
· Global Collaboration and aligning efforts with the International Labour Organisation (ILO) to embed heat protection into fundamental labour rights.
Things have certainly moved on since we first discussed protection for outdoor workers in jobs such as agriculture and construction in 2020. Twenty -one countries have now passed legislation to that effect.
While others are still in the process of developing National Guidelines, some states, particularly California in the USA and The Northern Territory and Queensland in Australia, are going it alone. Others rely on employer discretion or their general Occupational Health and Safety laws. Many now also include indoor workers and a much broader range of outdoor occupations. Some examples follow:
KAustralia
- Though Australia doesn’t have a national standard yet, pressure is mounting from unions and health bodies. See general guidelines here.
- Queensland & the Northern Territory (among our hottest states) have guidelines for outdoor work, including mandatory rest breaks and hydration protocols.
- Employers must reduce work hours or suspend outdoor operations when temps exceed 35°C –40°C. The law also calls for mandatory cooling breaks, protective gear, and heat illness training.
- Use maximum temperature thresholds to trigger work stoppages or schedule changes.
- Some sectors, particularly in construction and agriculture, have collective agreements that mandate early shifts or heat allowances.
- Use Wet Bulb Globe Temperature (WBGT) to assess heat stress. (see previous post)
- Employers must monitor indoor and outdoor conditions and adjust workloads accordingly.
- Qatar has been having temperatures above 50oC. Its new legislation states that outdoor work cannot be done between 10 am and 3 pm from June 1 to September 15, unless it is in a shaded and artificially ventilated area.
- However, even the latter must stop if the WBGT reading is above 32.1 o C.
- New hires and people who have been absent for a period must be allowed to become acclimatised slowly.
- Workers must be allowed to set their own pace with respect to rest breaks and the employer must provide adequate water, shaded rest areas and protection from solar radiation. Read more here.
How to Make A Heat Stress Plan
I haven't looked at all the permutations on these but South Africa's offers straightforward checklists and things employers should look out for. For example, when inspecting the workplace regarding heat stress, not only temperature, but other factors such as humidity, airflow and radiant heat emitted from equipment and processes, as well as the length of exposure, should be taken into account.
The next step is to look at the work itself - does it involve physical exertion, complexity, or require more concentration? And how are the workers? Are they older or younger? Experienced or inexperienced? Acclimatised to local conditions? Are any workers pregnant or suffering from any other condition which may be exacerbated by heat stress such as diabetes or heart disease, or are they taking any medications which could affect their response?
This is followed by a hierarchy of ways to mitigate against heat exposure, starting with eliminating the hazard altogether, as the preferred option.
1. Eliminating the hazard where possible, by using automation for example
2. Using engineering solutions such as shielding or enclosure to prevent heat reaching workers. Humidity can be reduced by covering open water baths or providing humidifiers.
3. Administrative solutions involve restricting access during the hottest times of day, job rotation and more work and rest cycles, so workers have a chance to cool off in between. Provision of information and training, first aid equipment and ample fluids are also essential.
4. Personal Protection Equipment (PPE) such as heat -resistant clothing, sunglasses to shield against excessive UV and so forth, should be the last line of defence.
The Canadian* version is somewhat more complex, but it explains in great detail how to read a Wet Bulb Thermometer and how temperatures can vary in different parts of the workplace. Most importantly it shows different temperature thresholds for different types of work -those for an office worker for example, will most likely be higher than for someone working in a foundry or a bakery. Here are a few other tips from theirs:
1. Canada’s plan mentions using mechanical aids such as trolleys and turntables to reduce the amount of physical exertion required
2. Creating a buddy system at work, so employees keep an eye on one another to make sure neither is starting to show signs of heat stress
3. The importance of reporting discomfort early
4. Also stresses the importance of awareness and training
5. Recommends avoiding caffeine, sugared drinks and alcohol on days of high heat stress because they contribute to dehydration
6. Recommends having drinking water or electrolytes on hand and reminding people to drink often, even when not feeling thirsty. (EVERYONE SAYS THIS, not just the Canadians!).
7. Additional advice from the WHO, the ILO (International Labor Organisation) and WorkSafe Australia, is to have additional staff during hot periods, to allow for regular rotation.
*Canada uses a different temperature measure Humidex which combines humidity and temperature, but doesn't account for other factors such as wind, solar radiation, clothing or activity level. A Humidex of 40 + is dangerous to health and can cause heat stroke.
Comparison of Heat Stress Indices
Humidex vs. UTCI vs. WBGT
UTCI (Universal Thermal Climate Index) • Integrates temperature, humidity, wind, solar radiation, and physiological modeling. • Designed for outdoor thermal stress across climates. • Highly accurate, but complex to calculate. • Ideal for climate research, urban planning, and nuanced forecasting.
WBGT (Wet Bulb Globe Temperature) • Combines wet bulb, dry bulb, and globe temperature (solar radiation). • Used in occupational safety and sports to set work/rest limits. • Requires specialized equipment. • Less intuitive, but effective for exertion-based heat risk.
Humidex (Canada) • Combines temperature + humidity to express how hot it feels. • Simple, public-facing index used in weather alerts. • Doesn’t account for wind, radiation, or activity level. • Good for general awareness, but limited in precision.
Below are some other occupations which are just starting to get more attention and which may not immediately spring to mind.
Truck Drivers, Delivery Drivers and Bus Drivers
The truck drivers' WorkPro site notes that truck drivers, delivery riders, and public transport operators spend hours in heat and UV -exposed cabins and on asphalt. Slower reaction times and cardiovascular strain are rising concerns, especially during loading and unloading. It also notes that productivity losses due to heat in the workplace cost Australian companies $6.9 billion a year. Here are its recommendations:
- Regular breaks in cool environments
- Access to air-conditioning or fans
- Hydration and UV protection
- Monitoring younger or newer workers more closely, as they’re statistically more prone to heat-related injuries
- Ensuring that drivers and their employers recognise the signs of heat stress.
Performers
Another group we don’t often think about are dancers, musicians or stage crews performing under intense lighting and in crowded spaces. Fortunately Griffiths University’s ETHOS project is incorporating climate resilience into theatre design and policy.
Outdoor Activities
Elite
sportspeople are well aware of the impact of extreme heat on performance and it
is also well known that heat stress and physical exertion add to the strain on
the cardiovascular system. Even watching sport or listening to a concert can
prove deadly, as the table below shows:
| Event | Location | Impact |
|---|---|---|
| 2020 NRL Preseason | Sydney | Player Keith Titmuss died from exertional heatstroke |
| 2019 Australian Open | Melbourne | Matches disrupted due to extreme heat; players collapsed |
| 2023 Sydney Marathon | Sydney | Multiple runners treated for heat-related illness |
| 2023 Taylor Swift Concert | Rio de Janeiro | 23-year-old fan died; 1,000+ fainted in 138°F heat index |
| 2023 Ed Sheeran Concert | Pittsburgh | 17 fans hospitalized for heat-related seizures and cardiac arrest |
Sporting Events
To prevent such incidents in future, the
Australian Institute of Sports Medicine has developed a straightforward, no -nonsense
guide for organisers, schools and the like. It includes how to determine what the
temperature and humidity are likely to be at a forthcoming event, a grading as
to the type of heat stress involved in particular sports, how to prepare for
them, when to introduce more
breaks, passive and active cooling measures, and what to watch out for if athletes, students or others are experiencing heat stress.
That chart should be on the wall in all workplaces,
schools and public places, so that we all recognise heat stress and know how to
respond.
Key features of Event plans now include the following:
· Scheduling events outside peak heat hours.
· Providing cooling tents, misting stations, and free water.
· Training staff to recognise early signs of heatstroke.
· Adjusting rules to allow extra breaks and medical checks.
In hot places like Australia, don't forget to protect your eyes from sun damage either, because excessive UV exposure can cause macular degeneration or that scourge of surfers -ptergium which can however, also affect farmers and any other person who spends a lot of time outdoors without wearing a wide brimmed hat and or at least a good pair of sunglasses.
The Conversation has more here for both organisers and fans. The USA has also produced some excellent guidelines regarding outdoor events and particularly with respect to protecting spectators, not just athletes. Learn more about Heat and Sport here or about best practice for Heat Safety for spectators.
Concerts
As far as live performances go, Australia has updated Heat -Specific Guidelines for Events (2024). These outline the promoters’ and venue operators’ duty -of -care and their responsibility to provide heat stress mitigation for workers and patrons. These include provision of shade, water and medical support. Failing to do so could result in fines or shut downs under Work Health and Safety Laws. Some states require heat risk documentation as part of event approval.
Western Australia’s 2022 Guidelines for Concerts and Gatherings are stricter and include updated sections about :
- Medical risk tools to assess heat-related illness potential
- Crowd care and peer support during high-temperature events
- Emergency management planning, including hydration stations and shaded rest zones
NSW Health’s Music Festival Guidelines (2024) also require:
Risk assessments for heat exposure
- On-site medical teams trained in heat illness response
- Shade, water and cooling zones as part of harm reduction strategy
Looking After Vulnerable People
The Elderly and those with Disabilities or Existing Illnesses
Australia
During the 2019–2022 period, Australians aged 65+ were the most frequently hospitalised for heat-related injuries, so several agencies responsible for aged care have created heatwave plans for elderly people in residential facilities as well as for those being cared for at home. The Department of Health for example, provides checklists and planning tools for both those in residential aged care and those who are being cared for in their homes.
The Aged Care Quality Commission urges facilities to monitor vulnerable residents, especially those with existing health issues or limited mobility and to support staff as well, because heat stress can impair decision-making and increase fatigue, heightening risks for both staff and residents. Other recommendations include the following:
- Creating a “vulnerable people list”
- Individual heat action plans
- Staff education on heat-related deterioration
You can find the full instructions in the booklet "Caring for Older People in Hot Weather" here
Special Provisions for those at Home
- Most of the above also apply to those at home, but the Health Department also recommends supplying air conditioning to those most at risk (rather than the general population) and not only installing these appliances, but showing people how to get the most out of them. It also recommends providing financial support, so that those at risk can do so without financial stress.
- Another important aspect is to have neighbours, family members, or community organisations check in on the elderly and those at risk at regular intervals during a heatwave.
- In parts of Australia, the Red Cross makes calls to vulnerable people on hot days. If there is no response, Emergency services are dispatched.
South Australia's Telecross REDi system is notable in that regard because it is more proactive and centralises the identification and prioritisation of at-risk individuals at the state level, rather than waiting for them to register. Read more here
Such callback services were pioneered in France in 2006 after the 2003 heatwave was found to have led to the death of 1294 Parisians. Since then, many countries have implemented similar services.
In the UK, for example, the National Health Service (NHS) and local councils tea up to carry out heatwave plans thato include outreach to vulnerable populations, often via community health workers or volunteers.In the USA, cities such as Chicago and Phoenix have emergency phone check-ins during extreme heat, especially for seniors and the homeless.
Europe
Twenty – one out of the 38 wider European Economic Area countries now also have Heat -Health Action Plans (HHAPs). Don't worry, I won't be listing them all - just enough to show what they have in common, but also how they differ in response to local or national priorities.
- Studies in the Netherlands & Germany prompted by the same 2003 heatwave, showed that there were one-third more deaths in nursing homes, than among elderly people in private homes. This led to a flurry of reforms in building design and emergency protocols, including hydration monitoring. Design changes included features such as shaded courtyards and cross-ventilation. Despire these changes, Germany has recorded 3000 excess deaths each year of the past two years due to heat stress.
· Denmark has gone further incorporating not only passive cooling strategies into Elder Care such as natural ventilation, solar shading, and thermal mass, but also uses assisted living technologies such as smart sensors and adaptive lighting to ensure thermal safety.
· In Hungary, specific recommendations are provided for social
institutions and children’s homes by the Department of Public
Health. These include improvements to buildings to better manage heat — such as
by installing external shading, using air conditioning and ensuring access to
indoor spaces with temperatures below 26°C. Social institutions are also
advised to continuously monitor vulnerable individuals, provide adequate
hydration and consider the potential impacts of those medications that can
increase heat sensitivity.
- The Italian National Heat Action Plan is designed to mitigate health risks associated with extreme heat events, particularly for vulnerable people such as the elderly, individuals with chronic diseases, outdoor workers and socially isolated individuals. Facilities working directly with elderly people are directed to encourage the consumption of drinks and hydrating food as well as to closely monitor at-risk patients.
- Furthermore, at the beginning of the summer, lists of vulnerable patients are made available to GPs in several cities, who evaluate whether to include said patients in active surveillance programs. This measure enables GPs to play a more active role in protecting elderly people living outside of care facilities from heat.
- North Macedonia's HHAP focuses on vulnerable groups including elderly people, infants, children, people with health conditions, socially isolated individuals, outdoor workers and people on low incomes. In hot weather, education, health and social care institutions caring for vulnerable populations are advised to implement short-term measures such as supplying air conditioners, providing cooling areas, ensuring access to drinking water and placing curtains on south-facing windows to keep heat out.
- In Sweden, Kristianstad Municipality's Heat Action Plan proposes several measures to keep vulnerable populations safe during hot periods. Healthcare providers are instructed to monitor for signs of heat-related illnesses such as heat exhaustion and heatstroke, particularly in individuals with pre-existing conditions and those such as the elderly, who are more vulnerable to heat.
The UK -A dual-layer heat alert system integrates public messaging with health-sector coordination. Care homes receive tailored guidance, and some have adopted reflective roofing and improved ventilation to reduce indoor temperatures during heatwaves.
South Korea: Mobile networks send personalised heat warnings to elderly residents. Cooling stations are backed by private firms like LG, and hospitals are retrofitted with passive cooling and backup power systems.
- Argentina: Urban cooling strategies include expanding green spaces and deploying reflective roof technologies in disadvantaged neighbourhoods. These are being piloted in aged care facilities to reduce heat-related mortality.
Children, Students and Young People
Note the attention being given to heat stress in children in several of the above plans. This is because research has shown that far from being more resilient as was previously assumed, children and especially infants, are even less able to dissipate heat. In part this is because of their smaller body size, their higher metabolic rate and because their thermo -regulatory systems are generally less developed.
Michael Hubmann, president of the German Association of Paediatricians and Adolescent Doctors (BVKJ), notes that between 2018 and 2022, almost 2,600 children and adolescents were treated for heat-related injuries per year on the 14 ‘heat days’ that exceeded 30 degrees Celsius. Over 1,000 newborns and infants with impaired breathing also receive medical treatment each year on heat days.
Infants are especially vulnerable because it's not as if they can transport themselves to a shady place or get themselves a glass of water. Older children may be able to do so, but not necessarily think of doing so. For this reason adults need to remind them and provide plenty of opportunities for refreshment and shade as well.
Anticipating more heatwaves in future, Andreas Storm, head of German Health Insurance Company DAK, says “We need effective heat protection from nurseries to schools, from playgrounds to football pitches. Children must not be neglected when designing and implementing heat protection plans. ”
- Some Australian states now require UV-safe play zones in early childhood centres, with Safe Work Australia recommending shaded areas, protective clothing, and scheduling outdoor play outside peak UV hours.
France has been creating "green oasis" schoolyards since 2017. It now has 165.
These redesigned spaces include:
-Unsealed surfaces for rainwater infiltration
-Drought-resistant vegetation and shaded play areas
-Pedagogical gardens for nature-based learning
-Cooling fountains and water games
-Open access to the public outside school hours
The Polish City of Poznań has been following France's example and began creating a network of playgrounds and green schoolyards since 2024. This idea is now being expanded to other cities as well.
Effects of Extreme Heat on Education
While the physical effects of higher temperatures are now generally understood, their insidious impact on psychological well -being, behaviour and learning are only just starting to emerge.
- In 2016 a small study in Boston showed that students without air conditioning took 13% longer to respond on a standardised test.
- A cross -cultural study by Stanford University involving 144 million 15 –19-year-old students in 58 countries, found that each day above 80o F resulted in a measurable decline in student performance which could have profound consequences for their chances in later life.
As days of heat stress increase - Youngzine notes that days above 80oF have steadily increased by almost 4.6 % in the USA over the last 4 years and children are now experiencing double the number of heat stress days that their parents did, it is of concern to teachers, medical professionals and others that 36,000 public schools in the USA do not have adequate cooling, heating or ventilation. [I am not sure Australian schools would fare much better!]
Researchers at the Centre for the Developing Child at the Harvard Graduate School of Education now making the following recommendations:
1. That all schools, childcare centres, holiday programs and after school activities be evaluated for their potential extreme heat stress exposure
2. Designing new buildings and retrofitting existing ones to be more energy efficient and reduce heat stress exposure, including many of the features in the previous post – using ‘cooling’ materials, cool roofs, pavements, and shade trees
3. Installing air conditioning or other cooling mechanisms which are less energy intensive – (fans, evaporative cooling, improved ventilation).
4. Consider switching to sustainable energy sources
5. Encouraging the development of Community Heat Action Plans.
- · Surveys of 355 Primary School teachers conducted in India in 2023 across seven cities, found that heat
stress played a major role in children’s ability to learn, teachers’ ability to
teach, absenteeism and heat related illnesses. Here are some of their suggestions to make life more bearable in those schools where air -conditioning is not an option:-Closure of schools on Government declared heat wave days.
-Ensuring that children wear loose light clothing – e.g.no ties, relaxation of uniform rules, canvas rather than leather shoes
-Shading of class rooms – many did not have internal blinds or curtains
-Limiting school hours. Earlier starts and earlier closing.
-Scheduling activities such as sports for the morning
-Informing children, parents and staff about heat risk and recognising the signs
-Having water, shaded areas and requisite first aid and emergency assistance on hand.
People on Low Incomes and Homeless People
- Miami-Dade County has a financial assistance program for low-income residents and maintains a list of resources for Florida incentives and rebates for energy savings and home cooling.
- The county’s HOMES plan, a housing affordability initiative
announced in 2022, includes $7 million for retrofitting and ‘weatherising’
older homes and includes requirements that new construction funded by the
county include cool roofs—light -coloured roofs made with materials that
reflect instead of absorbing heat, which can reduce cooling costs considerably.
- The city is also focused on improvements to the power grid, especially since hurricanes can leave residents sweltering without electricity for days or weeks.
- In the United States – California & Texas, some facilities have begun retrofitting with heat-reflective roofing, improved insulation and air circulation and emergency cooling protocols during heatwaves However, these efforts are often reactive and unevenly applied.
In Australia & New Zealand, some pilot programs include - thermal mapping of cells, Green infrastructure trials in juvenile facilities and staff training on climate-related emergencies
- As temperatures rise and heatwaves increase, UNICRI (United Nations Interregional Crime and Justice Research Institute) has published its Green Prisons: A Guide to Creating Environmentally Sustainable Prisons with the aim of not only making them cooler and greener, but helping to rehabilitate inmates and train them for green jobs.
Thank you to Copilot for the illustration, lots of answered questions and references and for help with the formatting which seems to be getting weirder with every passing update.
I did want to write about those other helpless captives - our farm animals, and there is indeed work underway to help them deal with extreme heat too, but that is likely to add another whole chapter, so will leave that for now. Do remember though, to leave out some extra water for the wild birds and beasts on those very hot days, including the insects - other than the mosquitoes! Bees love a damp cloth on the line.
I solemnly promise the next post will be shorter!
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