Heatwave relief: What can hot countries teach us about keeping cool?

As global warming - driven by our use of oil, gas and coal - spawns more deadly heatwaves worldwide, what can newly sweltering countries learn from heat-hardy ones about ways to stay cool?

With the mercury soaring this week, from Europe to Asia to the United States, here are a few ideas:

Think white

We know that white clothing is cooler on a hot day - similarly, using light-coloured roofing material or painting roofs white can help hold down the heat inside buildings.

In steamy Indonesia's industrial buildings, "cool roofs" are being used to drop indoor temperatures for workers by up to 10 degrees Celsius (18 degrees Fahrenheit), heat experts say.

In hot South Asian nations like India and Bangladesh, painting roofs white is becoming far more common too, particularly in neighbourhoods where many residents struggle to afford air-conditioning or the power bills to run fans.

It could also be time to ditch sweltering black tarmac surfaces. During the summer Olympics in Tokyo last year, the marathon route was covered in light-coloured reflective paint to try to keep temperatures bearable for runners.

Los Angeles also has experimented with painting streets white.

Seek out shade

As we all know, it's cooler in the shade, so adding sun canopies to exercise areas and public squares and creating shadier parks, streets and pathways can help people as they go about their daily activities.

Tel Aviv in Israel has installed light-coloured fabric sun shades in some of its public areas that can also carry light-weight solar panels. These illuminate the squares at night, making them safer and more attractive to use round-the-clock.

Medellin in Colombia has created a "green corridor" system designed to ensure many residents can get where they're going on foot or by bicycle largely in natural shade.

The city now has 30 green corridors of trees and other vegetation that provide an interconnected 20-km (12-mile) network of shady routes. 

Try low-cost cooling

In countries not used to heatwaves, few people have air conditioners - and for those on limited budgets, even running lots of fans can be expensive. 

But low-energy, low-cost options to cut heat abound, among them taking advantage of the cooling effects of water.

In sweltering eastern India, the poorest families use jute sacks soaked in water - arrayed on their tin roofs or hung in doorways - to cool their homes. Many also leave clay jugs of water outside on hot days, to assist those passing by.

In the Indian city of Ahmedabad, a pioneering heat action plan triggers a wide range of measures when temperatures hit dangerous levels, including deliveries of water to slum areas where supplies may be unreliable.

In newly hot places, planning ahead to ensure water and power supplies stay on is crucial to battling heat - and in cities short of water, spray parks can be more a more water-efficient way to cool people than swimming pools.

Or subsidize keeping cool

As global temperatures rise, cooling is increasingly recognised as a service that is as essential for health and safety as winter heating.

In New York, city officials have responded to worsening heatwaves by distributing cooling systems to some low-income seniors.

The city also is petitioning the state government to give poorer families financial aid to pay summer utility bills - just as some now receive help for winter heat.    

As well, it is considering setting a maximum permitted indoor summer temperature for rental properties, as it sets a minimum level for winter.

Berlin, meanwhile, is launching a "heat aid" programme for its homeless residents, with showers, sunscreen and drinks offered free to help keep those living on the streets safe.

Pick up the phone

The elderly, very young and people with pre-existing health conditions or disabilities can be particularly vulnerable to heat-related health problems, as can residents of inner-city communities with little access to parks or other cool spaces.

In some Australian cities, Red Cross workers now make calls to vulnerable people on hot days - and dispatch emergency services if they go unanswered.

Buenos Aires also reaches out to elderly residents with phone calls and texts when the heat rises.

Everywhere, simply checking on vulnerable neighbours during hot periods can help keep them safe, heat experts say.

Call in medical help

In some dangerously hot places, including some Indian cities, holidays for medical staff are suspended during heatwaves.

Spanish cities, meanwhile, are experimenting with placing ambulances at the beach to handle heat-stroke cases quickly.

Heatwaves can also affect mental health, particularly if people are unable to sleep - and can lead to an increase in work accidents and domestic violence.

Ensuring staff are in place to deal with calls for help can reduce risks, heat specialists say.

Provide warnings

In normally cool places unaccustomed to dealing with deadly heatwaves, many people rejoice at hot days - and are slow to recognise the risks as they become more severe.

Better warnings such as Britain's new heatwave alert system - which issued its first-ever "red alert" ahead of this week's heatwave - help people gauge the risks and give them time to prepare, from stocking up on fans and ice to changing travel plans.

Some experts have also suggested that naming heatwaves - as is done with hurricanes - could help raise wider public awareness of them as potential disasters.