Column

Protect people from extreme heat

By Gerardo Reyes Jr

May 08, 2024

Who among us are not alarmed with the surging temperatures that we have experienced since early this year with some cities in the country reaching 50 degrees Celsius?

In fact, a dangerous peak heat index of 46 degrees Celsius hounded Puerto Princesa City on April 22, 2024 while PAGASA warned that heat index this May 2024 might reachmore than 50 degrees Celsius.

The Department of Health (DOH) said that seven deaths have been recorded in the country this year.

As the temperature surges, the risks from extreme heat are also rising. Heat has always been a threat to urban living due to urban heat island (UHI). But climate change means that extreme heat now happens more frequently and more intensely compared to that in the past.

Heat can kill anywhere but the risk is greater in cities. In a study published in 2020 estimated that air temperatures in Pakistan and UAE cities have surpassed the human body’s limit of survivability on their hottest and most humid days.

For those of us living in cities, a hot, sunny day can feel brutal. Concrete buildings and asphalt roads trap heat from the sun and release it at night. Vehicle and air conditioning exhaust add to the UHI effect, in which cities stay warmer compared to their nearby areas.

It’s a fact that cities aren’t built to be cool—at least compared to uninhabited, vegetated spaces. Trees cool by providing shade and discharging moisture through their leaves. The cooling effect of a single healthy tree is equivalent to that of 10 air-conditioning units, which explains why a city’s coolest parts are those sporadically built or heavily vegetated.

Scientists said that these areas can be three to seven degrees cooler than built-up vicinities.

Climate researchers have long warned surging temperatures and increasing heat index. This means that city officials, engineers, architects, urban planners, stakeholders must work harder to incorporate extreme heat into climate-adaptation strategies.

A study in New Zealand shows that painting roofs white can keep homes cool without the need for expensive air conditioning. They call it ‘cool roofs’, which are painted white can reduce temperatures inside buildings by 2–5 °C compared with conventional roofing.

But this solution need to be done on a city-wide scale to achieve significant impact. To implement this, national government agencies and local government units need to require the construction firms to integrate heat mitigation in their building plan and designs through green building certification programs.

The provision of subsidies for green buildings is also an option.

Green corridors

One of the solutions to surging temperatures is city-wide network of cooling islands- including parks and pools- linked by cool walkways as showed by Paris in France and Medellin in Colombia. In Colombia, more than 10,000 trees have been planted along its 36 green corridors and this resulted to a 2-degree Celsius reduction in surface temperatures.

Government officials must continue to track the results of such experiments to show the best available evidence to green their cities.

As we face a future with longer, hotter dry weather, cities must intensify their planning for extreme heat. If our local disaster risk reduction and management councils have plans for other hazards such as floods, typhoons, fires, or storm surges, all of us should work to incorporate extreme heat into our local emergency plans. There’s no other way to counter it but to be prepared with it.