Monday, November 30, 2020

Keeping Our Cool -2 Other responses to extreme heat

A step in the right direction. This shelter in a public park not only provides shade, but protection from UV. We need much more of this - also water fountains and drink bottle filling stations, not only in parks but schools, sporting fields and other public spaces

Countries which have historically had warmer climates, have developed a number of ways to deal with extreme heat. For example, Spain and Latin American countries have traditionally had their siesta in the hottest part of the day and their homes make use of a number of passive cooling devices such as louvres which keep out the heat but allow airflow or incorporate features such as high ceilings and terrazzo floors which keep internal temperatures down.  In the Middle East there are features such as decorative breeze blocks, open courtyards, water features, thick stone or adobe walls and the abundant use of vegetation.  Windcatchers”  are a traditional Persian architectural element that provides passive cooling and ventilation by intercepting upper air currents and drawing them down into buildings. Many of these ideas are making a comeback. See more about passive cooling below and in the next post. 


Cooling Centres

With temperatures reaching 46oC (114.8oF) in Adelaide over the weekend, Fraser Island on fire and one child in Queensland dying from heat exposure after being left in a car, let’s start with those ideas which are the easiest to implement and then move on to those which require a more long term approach. Given that you are likely to be moved on by security if you hang about in libraries, cinemas and malls too long, many communities in the USA are providing “cooling centres’ where especially the frail and elderly can be brought for relief from hot weather. As I was writing this I heard that Melbourne has had some of these too, but no one knew that they existed. Perhaps now is the time to not only create more awareness about the dangers of extreme heat, but also to ensure that the public knows where these places are. In cosmopolitan places like Melbourne, this information should also be made available in other languages which would be of benefit to tourists as well. In Germany such places are more likely to be within facilities such as kindergartens, aged care establishments and so on, so that there is no need to travel in a heatwave.

Occupational Health

The EU which has had a comprehensive heatwave plan since the heatwave of 2003, has focussed primarily on early warning systems and occupational health. Project Heatshield as it’s called, has looked at several occupations which are more likely to experience heat stress - for example, the agricultural sector, construction, tourism and transport, all of which represent enormous value to the economy.  To its credit, the EU offers free customised consultations to businesses in member countries about ways in which they can adapt.

Rescheduling work

The plan for agricultural workers and construction workers is to schedule heavy work for cooler parts of the day, to make sure that there is always plenty of drinking water on hand, and to incorporate plenty of rest breaks in the shade.  The importance of this will be evident from the following story. A mystery illness which was killing sugar cane workers in Central America has now been found to be due to kidney failure caused by lack of hydration. Since such changes have been introduced, premature deaths from this cause have been greatly reduced.  

Not only do strokes and heart attacks become more frequent in the heat but mental confusion increases too, thereby also contributing to accidents especially in manufacturing, transport and construction. However, even office workers and students are prone to reduced performance and productivity in the heat, highlighting the importance of having adequate ventilation, cooling and water available in all workplaces, schools and community centres as the weather warms up.

 Rethinking Protective Clothing

Where protective clothing is required, there is now considerable emphasis on making it from breathable fabrics and incorporating fans and other forms of cooling such as using “phase change” fabrics. I think of those poor miners* in their heavy gear working in some of Australia’s hottest regions, or that worn by firefighters and can see that there is much room for improvement there. [By the way, the opal miners in places like Cooper Pedy, Lightning Ridge and Andamooka, where the temperatures often reach 50oC have long had the good sense to live underground!].

Protective Clothing (per the EU’s Project Heat Shield)


Sports

Not surprisingly, sports -mad Australia has considered the impact of heat on sporting activities a priority in its first Heatwave Plan, limiting the intensity and duration of play as the mercury climbs. When the wet bulb thermometer sits between 26 -29oC, intensity and duration of sport is to be limited and if above 30oC it should be postponed.  This plan, developed in around 2005, doesn’t seem to have had much publicity. Wish we'd known that when granddaughter had her sports carnival on one of the days when it was 32oC, especially as the venues tend to be open playing fields. Fortunately, a feature of more recent plans developed separately by various states is that there is more emphasis on such matters.

Planning for Higher Temperatures

Prominent among the the recommendations is the need for local councils to consider their infrastructure to take higher temperatures into account. It urges them to plant urban forests, create wetlands and use permeable surfaces – grass, green roofs etc. to trap moisture, provide shade and create heat sinks in order to combat the “urban heat island effect” wherein concrete and paving absorb and continue to radiate heat long after sundown.  A vertical wall of greenery on a building for example, can reduce heat on the adjacent pavement by up to 5oC. Provision of water fountains and drink –bottle filling facilities, along with shading of outdoor functions and venues will also become more important. In my humble opinion we should also be putting shade -cloth over open swimming pools and placing shaded enclosures at beaches because being in or around water tends to mask symptoms of heat stress. I also got my first taste of skin cancer after regular swims at an open pool in Perth. As job creation schemes go, this would have far greater future benefits than funding bathroom renovations for people with a spare $150,000 in the bank.

 

Transformation of a suburban street in Wyndam, near Melbourne by urban planner Ludo Campbell -Reid AKLdesign - Before....

After. I feel cooler already!

Building Cooler Homes

There is also much interest in building design which redirects heat, controls humidity and considers the thermal properties of building materials. India for example, which developed the first heat action plan for South East Asia in 2013 after its heatwave of 2010, recommends among other measures, painting roofs in white or reflective paint to keep out the heat. Insulation in attics and crawl spaces makes a big difference too. 

For other ways of keeping homes cooler without adding to electricity costs, see the excellent article by the Australian Government on passive cooling. With luck and foresight, more and more of these will find their way into our building regulations and planning laws which are also under the auspices of local councils.

It also falls to local and regional authorities to make sure that excessive heat doesn’t affect power supplies, IT services, food safety, water quality and the like. For example, algal blooms and salmonella poisoning are both likely to increase as temperatures rise. Power outages which also tend increase during heatwaves may compound both problems.  For a much more detailed discussion of these issues see the comprehensive “Minimising the Impact of Extreme Heat” guidelines developed by the state government of New South Wales. 

* Miners - I've since been speaking with my daughter who was a senior Occupational Health and Safety Officer with two of our biggest miners. She says things have improved a great deal since the last time I worked in or visited some of our mines.  Most mines now have “cool rooms” and all the equipment – the trucks and the diggers and so on, is air -conditioned too. Miners are supplied with water, ice machines and electrolytes at all times and as far as protective clothing goes, most of it is now vented and there are special features such as a collar which is kept cold and wet. More recent changes include jackets which both heat and cool, but these are still fairly rare. The biggest change though, she says, is the training. All miners are taught to recognise the signs of heat stress and to seek out First Aid and Medical Staff if they feel the slightest bit unwell.  

Unfortunately, the same doesn’t apply to our brave band of volunteer fire fighters. They need that heavy clothing to protect them from radiant heat and falling debris. Let’s hope nanotechnology will soon provide them with some relief.

Below are some other examples of Extreme Heat Plans:

South Australia -

Victoria

See also the World Health Organisation's general guidelines for Heatwave Planning:

"Heatwaves and Healt Guidance on Warning Systems Development (WHO #1142)

For the USA see the booklet by the EPA and CDC "Climate Change and Extreme Heat: What you can do to prepare"


https://www.pwc.com.au/industry/government/assets/extreme-heat-events-nov11.pdf

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