Cool places, first and last refuges against extreme heat waves

Since the traumatic experience of the 2003 heatwave, which caused the death of 15.000 people, mayors have been required to identify cool or air-conditioned places in their city and to keep a register of vulnerable people.

In the event of a heatwave, these people must be quickly sheltered by taking them to air-conditioned rooms.

But this system has largely "proven its ineffectiveness," notes Sébastien Maire, general delegate of the France Ville Durable association. Since registration is voluntary, the most isolated people, according to him, escape any census.

Since then, town halls have refocused their actions and communication on the presence of "refuge" places scattered throughout the towns.

This is the case in Paris, where 1.400 cool spots have been mapped "within a seven-minute walk": parks, misting areas, green streets, churches, swimming pools, air-conditioned museums or libraries...

"We're expecting temperatures of 50 degrees in the coming years. We're therefore in a race against time to deal with the effects of global warming," Dan Lert, deputy for ecological transition, told AFP.

"Heat Dome"

In 2023, a "Paris at 50°C" simulation exercise was conducted to anticipate a "heat dome." In their summary document, the city's services are considering the possibility of opening "other places of refuge" such as shopping centers, underground stations, or parking lots, and occupying them "for a long period," including "at night."

The tunnels of the Parisian inner ring road were also tested to teach students.

While some cities are more advanced, "rare are those that have a strategic approach to these places of refuge," acknowledges urban planner Clément Gaillard.

"If a catastrophic heatwave occurs tomorrow, we will urgently mobilize underground parking lots, buried sites and churches," assures this expert in bioclimatic design, recalling that there is a "huge pool of abundantly air-conditioned buildings, such as shopping centers."

Today, cities are favoring solutions that are easy to implement from a technical and legal perspective. This is the case in Saint-Genis-Laval, a town of 21.000 inhabitants on the outskirts of Lyon, where the air-conditioned city council chamber is adapted in the summer to accommodate an intergenerational audience.

In Toulouse, the emphasis was placed on extending the evening closing hours of parks, swimming pools, museums and libraries, as well as on making cultural venues free.

"Sleeping outside"

Another solution that is very popular with municipalities is the planting of greenery in schoolyards, which in theory allows vulnerable groups to be accommodated outside of school hours.

"It's not air conditioning, but cooling by a few degrees," observes Sébastien Maire, who is "not certain that this will be sufficient from a health perspective."

He also defends the idea of ​​air-conditioning certain school playgrounds to make them real "refuge zones" and avoid "everyone having to equip themselves with individual air conditioners", but also "cold networks" and the mobilization of "private land, such as the interior courtyards of buildings".

"If the heatwave is really intense, there won't be enough cool places and it will be necessary to be able to sleep outside, especially in parks, which raises the question of surveillance and psychological obstacles," says geographer Anne Ruas.

In working-class neighborhoods where unrenovated housing is a thermal sieve, access to cool areas is all the more crucial as residents often lack the resources to escape the heat.

"There are pockets of cool air, but there aren't enough of them," notes Sanaa Saitouli, co-founder of the Banlieues Climat association.

However, the least wealthy municipalities are often those that invest the least in cooling solutions.

"There are communities that are very committed to protecting their populations from the heat, but the government is depriving them of financial resources, while many others have not grasped the extent of the urgency," says Robin Ehl, campaign manager at Oxfam.