The UK and Europe have been facing extreme heatwaves – Greenpeace recorded temperatures of up to 53C at one London playground in recent weeks. It’s clear our cities are not equipped to deal with the soaring temperatures brought by the climate crisis. With the ‘Super El Niño’ on its way, next year is forecast to get even hotter. But is anyone really doing anything about it? The Guardian’s deputy opinion editor Kirsty Major goes in search of playgrounds that are adapting to our new reality