Heatwaves threaten Australians’ health, and our politicians aren’t doing enough about it


Paul Beggs, Macquarie University; Helen Louise Berry, University of Sydney; Martina Linnenluecke, Macquarie University, and Ying Zhang, University of Sydney

Extreme heat affects the mental health of Australians to the same degree as unemployment, yet Australia’s policy action on climate change lags behind other high-income countries such as Germany and the United Kingdom.

As Australia approaches another summer, we face the inevitability of deadly heatwaves. Our report published today in the Medical Journal of Australia concludes that policy inaction, particularly at the federal level, is putting Australian lives at risk.

The report, The MJA–Lancet Countdown on health and climate change: Australian policy inaction threatens lives, builds on an earlier publication in The Lancet medical journal, which concluded climate change is the biggest global health threat of the 21st century.




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Australia is the first to prepare its own country-level report. Developed in partnership with the Lancet Countdown – which tracks the global connections between health and climate change – it adopts the structure and methods of the global assessment but with an Australian focus.

How Australians’ health suffers

Australians are already facing climate change-related exposures that come from increasing annual average temperatures, heatwaves and weather-related disasters. Australian deaths during the 2014 Adelaide heatwave and Melbourne’s 2016 thunderstorm asthma event are examples of the risk climate poses to our health.




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Our report was produced by a team of 19 experts from 13 universities and research institutes. We aimed to answer what we know about climate change and human health in Australia and how we are responding to this threat, if at all.

To do this, our team examined more than 40 indicators that enable us to track progress on the broad and complex climate change and human health issue. Health impact indicators included the health effects of temperature change and heatwaves, change in labour capacity, trends in climate-sensitive diseases, lethality of weather-related disasters and food insecurity and malnutrition.

We also developed an indicator for the impacts of climate change on mental health. This involved examining the association between mean annual maximum temperatures and suicide rates for all states and territories over the last ten years.

We found that, in most jurisdictions, the suicide rate increased with increasing maximum temperature. In Australia’s changing climate, we urgently need to seek ways to break the link between extreme temperature and suicide.

Across other indicators, we found workers’ compensation claims in Adelaide increased by 6.2% during heatwaves, mainly among outdoor male workers and tradespeople over 55 years.

And we found the length of heatwaves increased in 2016 and 2017 in Australia’s three largest cities – Sydney, Melbourne and Brisbane. Heatwave length varied from year to year, but between 2000 and 2017, the mean number of heatwave days increased by more than two days across the country.

Policy action we need

Australia’s slow transition to renewables and low-carbon electricity generation is problematic, and not only from a climate change perspective. Our report shows that pollutants from fossil fuel combustion cause thousands of premature deaths nationwide every year. We argue even one premature death is one too many when there is so much that we can do to address this.

Australia is one of the world’s wealthiest countries with the resources and technical expertise to act on climate change and health. Yet Australia’s carbon intensity is the highest among the countries we included in our comparison – Germany, United States, China, India and Brazil.

A carbon-intensive energy system is one of the main drivers behind climate change. Australia was once a leader in the uptake of renewables but other nations have since streaked ahead and are reaping the benefits for their economies, energy security and health.

Despite some progress increasing renewable generation, it’s time we truly pull our weight in the global effort to prevent acceleration towards dangerous climate change.

Policy leaders must take steps to protect human health and lives. These include strong political and financial commitments to accelerate transition to renewables and low-carbon electricity generation. The government lacks detailed planning for a clean future with a secure energy supply.




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Our MJA-Lancet Countdown report will be updated annually. Now that Australia has begun systematically tracking the effects of climate change on health – and given its poor performance compared with comparable economies globally – further inaction would be reckless.The Conversation

Paul Beggs, Associate Professor and Environmental Health Scientist, Macquarie University; Helen Louise Berry, Professor of Climate Change and Mental Health, University of Sydney; Martina Linnenluecke, Professor of Environmental Finance; Director of the Centre for Corporate Sustainability and Environmental Finance, Macquarie University, and Ying Zhang, Associate Director, Teaching and Learning, Sydney School of Public Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Why daily doses of nature in the city matter for people and the planet



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Brisbane’s South Bank parkland isn’t exactly getting out in the wild, but experiences of urban nature are important for building people’s connection to all living things.
Anne Cleary, Author provided

Anne Cleary, Griffith University

The environmental movement is shifting away from focusing solely on raising awareness about environmental issues. Many environmental agencies and organisations now also aim to connect people with nature, and our new research suggests daily doses of urban nature may be the key to this for the majority who live in cities.

Every year in the United Kingdom the Wildlife Trusts run the 30 Days Wild campaign. This encourages people to carry out a daily “random act of wildness” for the month of June. The International Union for Conservation of Nature recently launched its #NatureForAll program, which aims to inspire a love of nature.

This shift in focus is starting to appear in environmental policy. For example, the UK’s recent 25-year environment plan identifies connecting people with the environment as one of its six key areas. Similarly, in Australia, the state of Victoria’s Biodiversity 2037 plan aims to connect all Victorians to nature as one of two overarching objectives.

The thinking behind such efforts is simple: connecting people to nature will motivate them to act in ways that protect and care for nature. Evidence does suggest that people who have a high nature connection are likely to display pro-environmental attitudes and behaviours.

Looking beyond the park

What is less clear is how to enhance an individual’s nature connection – that is feeling that they are a part of nature. Over half of all people globally, and nine out of ten people in Australia, live in urban environments. This reduces their opportunities to experience and connect with nature.

Our new study may offer some answers. A survey of Brisbane residents showed that people who experienced nature during childhood or had regular contact with nature in their home and suburb were more likely to report feeling connected with nature.

The study used a broad definition of urban nature to include all the plants and animals that live in a city. When looking to connect urban residents with local nature we need to take a broad view and look “beyond the park”. All aspects of nature in the city offer a potential opportunity for people to experience nature and develop their sense of connection to it.

Raffles Place, Singapore – all urban nature should be seen as an opportunity for nature connection.
Anne Cleary, Author provided

The study also looked at the relationship between childhood and adult nature experiences. Results suggest that people who lack childhood experience of nature can still come to have a high sense of nature connection by experiencing nature as an adult.

There have been focused efforts on connecting children to nature, such as the Forest Schools and Nature Play programs. Equal effort should be given to promoting adult nature experiences and nature connection, particularly for people who lack such experiences.

The benefits of nature experience

We still have much to discover about how an individual’s nature connection is shaped. We need a better understanding of how people from diverse cultural and social contexts experience and connect to different types of nature. That said, we are starting to understand the important role that frequent local experiences of nature may play.

In addition to boosting people’s sense of nature connection, daily doses of urban nature deliver the benefits of improved physical, mental and social wellbeing. A growing evidence base is showing that exposure to nature, particularly in urban environments, can lead to healthier and happier city dwellers.

Robert Dunn and colleagues have already advocated for the importance of urban nature experiences as a way to bolster city residents’ support for conservation. They described the “pigeon paradox” whereby experiencing urban nature, which is often of low ecological value – such as interactions with non-native species – may have wider environmental benefits through people behaving in more environmentally conscious ways. They proposed that the future of conservation depended on city residents’ ability to experience urban nature.

As new evidence emerges we need to build on this thinking. It would seem that the future of our very connection to nature, our wellbeing and conservation depend on urban people’s ability to experience urban nature.The Conversation

The pigeon paradox: interactions with urban nature – here in London’s Hyde Park – may help make city dwellers more environmentally conscious.
Anne Cleary, Author provided

Anne Cleary, Research Fellow, School of Medicine, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

From Kilimanjaro to Everest: how fit do you have to be to climb a mountain?



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Climbing a mountain has more to do with how your body deals with altitude, which you can’t control.
from http://www.shutterstock.com

Julien Periard, University of Canberra and Brad Clark, University of Canberra

Since the commercialisation of high altitude mountaineering in the 1990s, the number of climbers has increased significantly. Mount Kilimanjaro, perhaps the most popular mountaineering trip in the world, now attracts around 40,000 climbers per year. And the number attempting summits above 8,000m (such as Mount Everest) has risen exponentially.

The main challenge for all climbers is the decrease in barometric pressure and thus reduction in oxygen availability as altitude increases. The severity of altitude is defined as low (500 to 2,000m), moderate (2,000 to 3,000m), high (3,000 to 5,500m), or extreme (above 5,500m).

Remaining at high altitudes severely affects our physical capacity, cognitive function, body mass and composition, and ability to ward off illness.

If we don’t acclimatise or stagger our ascent, we’re at greater risk of acute mountain sickness, high altitude pulmonary oedema (excess fluid in the lungs) and cerebral oedema (fluid on the brain). These illnesses are all commonly characterised by symptoms such as headache, loss of appetite, nausea, weakness, light-headedness, and sleep disturbance. The presentation of these illnesses often requires retreat to lower altitudes and in severe cases, evacuation via airlift from camp.

These conditions are among the greatest obstacles to successful summit attempts, particularly when ascending quickly.




Read more:
How does altitude affect the body and why does it affect people differently?


Acclimatising

Being fitter does not protect against altitude-related illness, nor does it ensure tolerance of the physiological challenges associated with high altitude exposure.

So acclimatisation is the more important factor. Acclimatisation is the process your body follows to adapt to the drop in oxygen availability. This is the best non-pharmaceutical strategy to prevent altitude sickness.

Mountaineers and trekkers can achieve acclimatisation by staying at moderate altitude (2,000-3,000m) for a few extra nights, then implementing a staggered ascent to higher altitudes. Gains in altitude should be between 300 and 600m of vertical elevation per day.

While many commercial trek schedules include rest days and acclimatisation days, some involving less technical climbing often ascend quite quickly. Some groups will ascend Kilimanjaro in four to five days (5,895 m).

To prepare for more rapid ascents, mountaineers may include some pre-trek acclimatisation, using natural or artificial environments to encourage their bodies to adapt.

Acclimatisation using artificial environments is known as “acclimation”. It can be achieved by either hypobaric hypoxia (normal oxygen concentration, lower barometric pressure), or more commonly via normobaric hypoxia (normal barometric pressure, lower oxygen concentration) using altitude tents or environmental chambers.

Technical experience, fitness and acclimatisation are equally important.
from http://www.shutterstock.com

Of the two approaches, hypobaric hypoxia appears to be better for acclimation, though it relies on access to a hypobaric chamber or an ability to live at moderate/high natural altitude.

Although still relying on specialised equipment and expertise, more environmental chambers available mimic normobaric hypoxia. In some instances, you can even use tent or mask systems in your own home.

Acclimatisation can also mitigate the effects high altitude will likely have on exercise performance.

Training

Although fitness is not related to incidence rates of altitude sickness, trek schedules typically require many hours of hiking, often carrying a loaded pack, over at least four to five days. When combined with the gain in elevation, this means seven to eight hours per day of hiking at a moderate intensity, often over varied terrain.

So a program of targeted training will ensure trek participants are able to meet the strenuous demands of high altitude hiking and mountaineering. Evidence suggests fitter hikers report a lower sense of effort and lower levels of fatigue during high or extreme altitude trekking.




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Studies have also found experienced mountaineers don’t need to expend as much oxygen, which is valuable when there’s less of it available. So to further prepare for high altitude expeditions, trek participants should focus on building fitness over several months by trekking at lower altitudes and carrying loads of 20-30kg for several hours over varied terrain.

This can be extended to higher altitudes (3,000m to 4,000m) and several consecutive days and weeks to allow for developing the strength required to tolerate the rigours of extreme mountain climbing. This is especially important as muscle mass and body fat losses occur during the expedition.

For ascents above 8,000m such as Mount Everest, the trekking company will usually have specialised training approaches. This may involve at least one year of training in which trekking time, distance and altitude are increased progressively, as summit day can take up to 20 hours. Experience in high altitude climbing and sumitting peaks between 6,000m and 8,000m is also required before attempting peaks of this altitude.

Staged ascents and considered approaches to acclimatisation are most likely to protect against altitude illness and ensure trek success. This involves using a planned approached to climbing with altitude targets allowing for acclimatisation.

The ConversationImproving overall fitness and gaining mountaineering experience will prepare trekkers for the physical, psychological and technical challenges presented by high and extreme altitude adventures.

Julien Periard, Associate Professor, University of Canberra and Brad Clark, Researcher, University of Canberra

This article was originally published on The Conversation. Read the original article.

How does altitude affect the body and why does it affect people differently?



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How well you’ll cope on a mountain has little to do with how fit you are.
wynand van poortvliet unsplash, CC BY-SA

Brendan Scott, Murdoch University

Every year, thousands of people travel to high-altitude environments for tourism, adventure-seeking, or to train and compete in various sports. Unfortunately, these trips can be marred by the effects of acute altitude sickness, and the symptoms vary from person to person. To understand why people are affected differently, we have to look at how the body is affected by altitude.




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From Kilimanjaro to Everest: how fit do you have to be to climb a mountain?


How is ‘altitude’ different to sea level?

Air is comprised of different molecules, with nitrogen (79.04%) and oxygen (20.93%) making up the majority of each breath we take. This composition of air remains consistent, whether we are at sea level or at altitude.

However, with altitude, the “partial pressure” of oxygen in this air (how many molecules of oxygen are in a given volume of air) changes. At sea-level, the partial pressure of oxygen is 159 mmHg, whereas at 8,848m above sea level (the summit of Mt Everest), the partial pressure of oxygen is only 53 mmHg.

At high altitudes, oxygen molecules are further apart because there is less pressure to “push” them together. This effectively means there are fewer oxygen molecules in the same volume of air as we inhale. In scientific studies, this is often referred to as “hypoxia”.



Author provided/The Conversation, CC BY-ND

What happens in the body in high altitudes?

Within seconds of exposure to altitude, ventilation is increased, meaning we start trying to breathe more, as the body responds to less oxygen in each breath, and attempts to increase oxygen uptake. Despite this response, there’s still less oxygen throughout your circulatory system, meaning less oxygen reaches your muscles. This will obviously limit exercise performance.

Within the first few hours of altitude exposure, water loss also increases, which can result in dehydration. Altitude can also increase your metabolism while suppressing your appetite, meaning you’ll have to eat more than you feel like to maintain a neutral energy balance.

When people are exposed to altitude for several days or weeks, their bodies begin to adjust (called “acclimation”) to the low-oxygen environment. The increase in breathing that was initiated in the first few seconds of altitude exposure remains, and haemoglobin levels (the protein in our blood that carries oxygen) increase, along with the ratio of blood vessels to muscle mass.

Despite these adaptations in the body to compensate for hypoxic conditions, physical performance will always be worse at altitude than for the equivalent activity at sea level. The only exception to this is in very brief and powerful activities such as throwing or hitting a ball, which could be aided by the lack of air resistance.




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Why do only some people get altitude sickness?

Many people who ascend to moderate or high altitudes experience the effects of acute altitude sickness. Symptoms of this sickness typically begin 6-48 hours after the altitude exposure begins, and include headache, nausea, lethargy, dizziness and disturbed sleep.

These symptoms are more prevalent in people who ascend quickly to altitudes of above 2,500m, which is why many hikers are advised to climb slowly, particularly if they’ve not been to altitude before.

It’s difficult to predict who will be adversely affected by altitude exposure. Even in elite athletes, high levels of fitness are not protective for altitude sickness.

There’s some evidence those who experience the worst symptoms have a low ventilatory response to hypoxia. So just as some people aren’t great singers or footballers, some people’s bodies are just less able to cope with the reduction in oxygen in their systems.

There are also disorders that impact on the blood’s oxygen carrying capacity, such as thalassemia, which can increase the risk of symptoms.

But the best predictor of who may suffer from altitude sickness is a history of symptoms when being exposed to altitude previously.

How are high-altitude natives different?

People who reside at altitude are known to have greater capacity for physical work at altitude. For example, the Sherpas who reside in the mountainous regions of Nepal are renowned for their mountaineering prowess.

High-altitude natives exhibit large lung volumes and greater efficiency of oxygen transport to tissues, both at rest and during exercise.

While there is debate over whether these characteristics are genetic, or the result of altitude exposure throughout life, they provide high-altitude natives with a distinct advantage over lowlanders during activities in hypoxia.

The ConversationSo unless you’re a sherpa, it’s best to ascend slowly to give your body more time to adjust to the challenges of a hypoxic environment.

Brendan Scott, Senior Lecturer (S&C), Murdoch University

This article was originally published on The Conversation. Read the original article.

Your asthma puffer is probably contributing to climate change, but there’s a better alternative



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There is an environmentally friendly option.
from http://www.shutterstock.com

Brett Montgomery, University of Western Australia

I breathe all the way out. There’s a quiet puff of gas from my inhaler, and I breathe all the way in. I hold my breath for a few seconds and the medicine is where it needs to be: in my lungs.

Many readers with asthma or other lung disease will recognise this ritual. But I suspect few will connect it with climate change. Until recently, neither did I.

In asthma, there is narrowing of the airways that carry air into and out of our lungs. The lining of the airways becomes swollen, muscles around the airways contract, and mucus is produced. All these changes make it hard to breathe out.

The most commonly used medicines in asthma are delivered by inhalation. Inhaling gets the medicines straight to the airways, speeding and maximising their local effects, and minimising side effects elsewhere compared to, say, swallowing tablets.

Some medicines (“relievers”) work quickly to relax the airway muscles. Others (“preventers”) work more slowly but do more good, preventing asthma’s swelling and inflammation of the airways.




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These medicines are available in various sorts of inhaler devices. The devices fall into two broad types: “metered dose inhalers” and “dry powder inhalers” of various shapes and sizes.

In metered dose inhalers, the medicine and a pressurised propellant liquid are mixed together in a little canister, and then sprayed out of the inhaler in a measured puff of fine mist. This is inhaled, often after passing through a “spacer” which allows more of the medicine to reach the lungs. While the medicine is absorbed by the body, the propellant, now a gas, is exhaled unchanged.

In dry powder inhalers, the medicine is in the form of a fine powder which is swept into the lungs as the user breathes in — there is no spray and no spacer.

Powder inhalers don’t release any gases at all.
Author provided

It’s feasible for many (but not all) people to use either sort of device. Young children do better with metered dose inhalers and spacers, as do people who struggle to inhale. But most asthmatics can inhale well from dry powder inhalers.

The two types of inhaler seem to work just as well as each other; if anything the dry powder ones might be a little better.

Metered dose inhalers are more often prescribed than dry powder devices in many countries, but this has more to do with history and familiarity than effectiveness.

What about those gases?

You might remember hearing, years ago, about “CFCs” — chlorofluorocarbons — and their dire effect on the ozone layer. A successful international treaty, the Montreal Protocol, led to their phase-out from various uses, including medical inhalers. And with that, I thought, the environmental problems of inhaler gases had ended.




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But CFCs were replaced with “HFCs” — hydrofluorocarbons — which are safe for the ozone layer, but which are potent global warming gases. HFCs are better known in their role as refrigerant gases in air conditioners and refrigerators.

A recent amendment to the Montreal Protocol has now planned a phase-out of HFCs, too, but it’s slow, with deadlines decades away. Earlier prudent management of these gases could make a big difference to climate change.

The one most often found in asthma metered dose inhalers, norflurane, is 1,430 times more potent than the best-known warming culprit, carbon dioxide. Another, apaflurane, is 3,220 times more potent than carbon dioxide.

Such warming power explains why even the small amounts in an inhaler are significant. Globally, tens of millions of tons of carbon dioxide equivalent are attributable annually to these inhaler gases.

How much pollution are inhaler gases responsible for in Australia? I wrote to several companies marketing asthma inhalers in Australia, asking them how much of these gases are present in their products. Some gave straight answers, but some hedged on grounds of commercial confidentiality. This makes it hard for me to be exact.

But based on some reasonable assumptions, and multiplying these by the number of inhalers dispensed on our Pharmaceutical Benefits Scheme last year, I tallied nearly 116,000 tonnes of carbon dioxide-equivalent pollution.

That’s equivalent to the emissions of about 25,000 cars annually. And this is surely an underestimate, as it doesn’t account for reliever inhalers sold over the counter. A person using a preventer inhaler monthly, plus the odd reliever inhaler, could easily release the annual equivalent of a quarter of a ton of carbon dioxide — that’s like burning 100 litres of petrol.




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How to change

The good news is, for many people with asthma, there’s an easy solution: shifting from metered dose inhalers to dry powder inhalers. As above, this won’t suit everyone, but will be possible for many.

I am both a doctor and a person with asthma. As an asthmatic, I’ve found changing inhalers to be easy — if anything, my dry powder inhalers are simpler to use. And as a doctor, I’ve been pleasantly surprised by how open my patients have been to this topic. I worried people might find it weird their GP was raising environmental issues at their appointment, but my fears were unfounded.

If you have asthma, a chat with your doctor or pharmacist would be a good way to gauge whether a dry powder inhaler is feasible for you. Don’t be surprised if they haven’t heard of this gas issue — awareness still seems limited.

The ConversationIf metered dose inhalers are a better choice for you, please don’t panic or quit your medicines. These gases probably won’t be the biggest contributor to your personal carbon footprint. Asthma control is really important, and these medicines work really well. But consider changing if it’s an option for you — when it comes to reducing our footprint, every little bit counts.

Brett Montgomery, Senior Lecturer in General Practice, University of Western Australia

This article was originally published on The Conversation. Read the original article.

Health Check: how can extreme heat lead to death?



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Our climate is going to get warmer, and we need to protect ourselves from heat-related illness.
from shutterstock.com

David Shearman, University of Adelaide

Our climate is becoming hotter. This is our reality. Extreme heat is already responsible for hundreds of deaths every year. It’s a big environmental killer, and deaths from heatwaves in Australian cities are expected to double in the next 40 years.

Those most at risk are the elderly, people with chronic illness, those living in socioeconomic disadvantage, outdoor workers, and athletes who play their sport in brutally high temperatures. But extreme heat can affect anyone at any age.

So, what happens in our body during times of extreme heat? And how can it lead to fatal consequences?




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How we lose and gain heat

Our core body temperature sits at around 37℃. If it rises or falls, a range of very efficient physiological mechanisms come into play. In good health, our body can usually cope well with deviations of about 3.5℃, but beyond that the body begins to show signs of distress.

In hot weather, the body maintains core temperature by losing heat in several ways. One is to transfer it to a cooler environment, such as surrounding air or water, through our skin. But if the surrounding temperature is the same or higher than the skin (greater than 35-37℃) the effectiveness of this mechanism is markedly reduced.

Blood vessels supplying blood to the skin dilate. This allows more warm blood to flow near the surface of the skin, where the heat can be lost to the air. That’s why some people’s skin looks redder in hot environments.

One way the body loses heat is by directly transferring it to a cooler environment.
from shutterstock.com

Evaporation (or sweat) is another way to lose heat from the body. If there is enough airflow and humidity is low enough, we can lose large amounts of heat through sweat. But on humid days, the rate of evaporation is reduced, as the air cannot absorb so much if it is already saturated with water vapour.

We can also reduce our heat production by resting. About 80% of the energy produced by working muscles is heat, so any activity will increase the amount of heat the body has to lose. This is why athletes and outdoor manual workers are at particular risk when performing at high levels of physical activity.




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What happens if the body can’t lose heat

Heat stress describes a spectrum of heat-related disorders that occur when the body fails to lose heat to maintain core temperature. Heat stress ranges from heat cramps to heat exhaustion (pale, sweating, dizzy and fainting). If the core temperature rises above 40.5℃, it can lead to heatstroke, which is a medical emergency, can occur suddenly and often kills.

The hypothalamus works as the body’s thermostat.
from shutterstock.com

Heatstroke is caused by a failure of the hypothalamus, the region of the brain that works as our thermostat and co-ordinates our physiological response to excessive heat. It’s what leads to mechanisms like sweating and rapid breathing, dilated veins and increased blood flow to the skin. So, when the hypothalamus fails, so does our ability to sweat and lose heat in other ways.

At temperatures higher than 41.5℃, convulsions are common. Irreversible brain damage can occur at temperatures above 42.5℃. Patients with heatstroke can show neurological signs such as lack of co-ordination, confusion, seizures and loss of consciousness.




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When sweating stops, the skin may become hot and dry, heart rate and breathing increase and blood pressure is low. Cells and nerves in the body become damaged. Liver damage is also common, but may not manifest for several days. The kidneys stop working, normal blood clotting is impaired, the heart muscle can be damaged and skeletal muscles start breaking down.

Essentially, this is what we describe as multi-organ failure. People with heatstroke can die within a few hours, or several days or even weeks later from organ failure.

Protecting yourself

Heatstroke could be “exertional”, as with athletes, or “classic”, which occurs in patients with impaired thermostatic responses, as a result of age, illness or medications.

Heatstroke can be caused by exertion, such as with athletes putting their body through stress in extreme temperatures.
from shutterstock.com

Much of the increase in deaths during hotter temperatures occurs in older patients with a chronic illness. This is because they may have a poorly functioning central nervous system that cannot orchestrate the physiological changes needed to lose heat.

Older hearts may not be able to cope with the changes in circulation needed for more blood flow to go to the skin. Some medications can also interfere with the mechanisms for heat loss.

People experiencing any of the warning signs of heat stress (headache, nausea, light-headedness and fatigue) need to alter their behaviour to reduce it.

The best way to do this is to find a cool spot indoors or in the shade, put on light clothing, avoid physical exertion, put a damp cloth on your skin, immerse yourself in cold water and stay well hydrated.

But for some people, like children who are too young to make changes to their environment (such as those left in cars), this is not possible. Also, for the elderly, perhaps those with chronic mental illness or on certain medications that impair their ability to respond to increasing core temperature, these signs may not be apparent or noticed.




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Strategies for coping with extremely hot weather


This means we need safeguards to ensure the vulnerable stay cool. This is especially a problem for elderly people who live alone.

So, as our climate warms up, we need to do all we can to minimise the consequences of an increasingly hot environment. That means we must adapt our behaviour, our understanding of the issues, our urban environments, our sporting events and our systems that look out for the vulnerable in our community.


The ConversationThis article was co-authored by Dr Mark Monaghan, an emergency physician, and Dr Liz Bashford, an anaesthetist, who are both members of Doctors for the Environment Australia.

David Shearman, Emeritus Professor of Medicine, University of Adelaide

This article was originally published on The Conversation. Read the original article.

How climate change affects the building blocks for health



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More intense rainfalls have caused flooding throughout New Zealand, as seen here in Northland.
from http://www.shutterstock.com, CC BY-ND

Alistair Woodward

In August last year, a third of the residents of the North Island township Havelock North fell acutely ill with gastroenteritis after their water was contaminated with campylobacter.

Following a long dry spell, the heaviest daily rainfall in more than ten years had washed the pathogenic organism from sheep faeces into the aquifer that supplies the town’s drinking water. The Havelock North supply, like many in rain-rich New Zealand, was not treated with chlorine or other disinfectants, and this was the country’s largest ever reported outbreak of waterborne disease.

This is just one example of how climate change may affect our health, according to a report released by the Royal Society of New Zealand today.

Prerequisites for good health

It turns out that the Goldilocks rule – “not too hot, not too cold” – applies to more than porridge. There have been many reports, such as those published by the Intergovernmental Panel on Climate Change and the Lancet Commission on Climate Change, that detail how aspects of human physical and mental are effected by a changing climate.

There is an optimum climate, related usually to what is most common or familiar. Deviations, especially if substantial and rapid, are risky.


Read more: Climate change set to increase air pollution deaths by hundreds of thousands by 2100


The RSNZ report is organised around eight prerequisites for good health, including community, shelter, water and food – all of which are threatened by climate change.

Building Blocks of Health Disrupted by Climate Change.
Royal Society of New Zealand

The building block metaphor is apt. It is unlikely that climate change will undermine health in new and unexpected ways. Instead we expect it to act as a threat multiplier. Where there are weaknesses in the foundations of public health, rapid changes in temperatures, rainfall and sea levels will magnify damaging effects.

Direct and indirect effects

The impacts will include direct effects. More intense rainfall, especially on the western side of the country, will test health protection systems, as in the case of Havelock North.

But the impacts may also be indirect. The RSNZ report points out that changes in the climate may disrupt ecosystems, with knock-on effects for human health. As water temperatures rise, algal blooms occur more frequently, and human pathogens such as the vibrio species are found in higher concentrations.

There may be more intense exposure to pollen and other allergens, a particular concern given the relatively high rates of asthma that apply in New Zealand.


Read more: Can we blame climate change for thunderstorm asthma?


A reliable supply of food is one of the most important ecosystem services. The global food system is simultaneously more productive than ever before, and also exquisitely vulnerable. We depend more and more on a small number of crops, grown in mono cultures on larger scale and in fewer locations, dependent on longer supply chains and frequently requiring irrigation and heavy use of artificial fertilisers.

Climate change threatens the production and distribution of food in many ways. For instance, the rice crop in southern China currently fails due to high temperature stress once every century or longer, but this will be a once-in-10-year event with 2–3°C global warming, and once every four years if average temperatures rise by 5–6°C.

Effects on mental health

Climate change also acts through social stressors. Rising sea levels, combined with heavy rainfall, threaten many settlements around the New Zealand coast and elsewhere. The community of South Dunedin is one of the most vulnerable.

On a broader scale, internationally, it is projected climate change will displace very large numbers of people. The recent flood of refugees to Europe (sparked, in part, by climate extremes) illustrates the detrimental effects to security, community cohesion and health that may result.

The RSNZ report acknowledges that it is not just physical health that is important. Depression, anxiety, grief and other manifestations of loss and conflict may occur when familiar environments are damaged and social connections threatened. This is most evident following disasters such as droughts and floods.

The report refers to the particular threat climate change poses to Māori. Not only are Māori over-represented amongst those with low incomes, and at greater risk therefore of poor health from hazardous environments. Māori culture also embodies a strongly developed sense of relationship with place that carries with it responsibility and obligations. Climate change challenges this guardianship role.

Transition risks and opportunities

There is another dimension to health impacts that is not discussed in the RSNZ report. I refer to the damage that may be caused by the way we respond to climate change. Mark Carney, governor of the Bank of England, calls them “transition risks”. These are not trivial concerns, Carney says, because managing climate change successfully will require radical change, and the implications may be far reaching.

Expanded use of biofuels might compete with food crops, for instance. Carbon- pricing regimes may also aggravate food insecurity in the poorest populations. In low-income countries, reducing numbers of livestock to control methane emissions might be detrimental unless there are alternative sources of protein, energy and nutrients.

However, there are opportunities, too. The co-benefits agenda gets only a brief mention in the RSNZ report, which is a pity, since win-win interventions may provide a politically palatable route to substantial cuts in greenhouse emissions. For example well designed, comprehensive taxes on food could avoid a billion tons of greenhouse gas emissions and also prevent half a million premature deaths each year.

This is particularly relevant to New Zealand and Australia as most of the gains would be made by cutting the consumption of red meat in rich countries.

The Royal Society report concludes that more research is needed to better quantify the health impacts of climate change. This is true, of course. But we know enough already about risks to pay close attention to potential solutions. The big question, in my view, is how we take carbon out of the New Zealand economy, rapidly, and in an equitable fashion, without disrupting the building blocks of health.

The ConversationMaybe we can do better than avoiding harm. Transport, agriculture, urban form, food systems – in these areas, and others, there are substantial opportunities as well as serious risks.

Alistair Woodward, Professor

This article was originally published on The Conversation. Read the original article.