ICT-based measures to cope with extreme temperatures

An intense heat wave could have severe consequences, including human life loss. The fallout of extreme temperature is becoming more and more serious in 21st century. Many urban areas and cities around the globe are finding it necessary to launch adaptation measures to tackle this climate change driven natural disaster. One of such cities is the City of Paris, where the heat wave of 2003 caused many  deaths among vulnerable Parisians. Recently, a mobile application, called EXTREMA Paris, was developed and released to help Parisians find “cool islands” in Paris, both during day and night. It inform in real time on their personalized health heat risk.

Paris in context

Paris will be a carbon neutral city and 100% powered by renewable energy by 2050. These targets have been set after the Paris City Council unanimously adopted a new Air Quality, Energy & Climate Action Plan (Plan Climat Air Energie territoriale, PCAET). This large plan aims to make Paris a fairer, more inclusive and resilient city.

The City of Paris is a leader in climate action. Adopted for the first time in 2007, then updated in 2012, the Paris Climate Action Plan is taking a new step in 2018. It pursues the goal of reaching 25% share of renewable energy (RE) in powering the city by 2020, increasing this to 45% share of RE by 2030, and ultimately making the city 100% reliant on RE by 2050.

With detailing more than 500 municipal actions in the Plan, organized around three timelines (2020, 2030, and 2050), the City sets new and ambitious goals to reduce its GHG emissions by 25% by 2020 (compared to 2004 levels), and further by 50% by 2030, and finally become carbon neutral by 2050.

The City’s ambitious carbon footprint target includes actions to tackle emissions associated with the food and construction sectors, and the transport outside of Paris, including air transport. Moreover, the City’s new measures under the waste sector (waste tax policy, waste to energy, etc.) are contributing to the achievement of the City’s climate targets.

The plan also focuses on sustainable food system, energy sobriety, and territorial adaptation measures. One of the City’s most recent climate change adaptation measures was the launch of EXTREMA Paris mobile app in summer 2018.


Description of the initiative

Today, extreme temperatures are attracting more attention as the cause of excess morbidity and mortality in communities. The heat wave of 2003 in Europe -with a death toll estimated to exceed 30,000. This made it the deadliest natural disaster in Europe in the last 50 years. It brought the severity of extreme temperatures’ consequences to the world’s attention.

France was hit especially hard as over 14,000 were reported dead – the highest number of casualties due to the heat wave among all European countries. Since then the City of Paris, with the highest number of victims among all French cities (+1,000 dead compared to regular summer), has adopted a range of adaptation measures to lessen the effects of heat waves in the city. In this respect, the most recent initiative that the City of Paris has taken is the launch of a mobile application called EXTREMA Paris in the end of June 2018.

The City of Paris, as a member of 100 Resilient Cities Network, in collaboration with National Observatory of Athens and by support of Aratos Systems has utilized the EXTREMA service and developed tailored EXTREMA Paris app. With this app, Parisians now have to look no further than their smartphones to find out where to go to cool off during a heatwave. Over 1,000 different places have been listed in this app as cool islands for those who seek refuge from high temperatures.

With the up-to-date datasets from Meteo-France, the EXTREMA Paris mobile app identifies areas of the city that are most affected by heat in real time. The mobile app assesses citizens’ personalized heat risk based on their location, and if the risk is high, alerts them. It also provides recommendations on how to respond to high temperatures and informs them about the cool islands around them and how to reach them.


▲ EXTREMA Paris mobile app views



On 23 November 2017 at the United Nations Campus in Bonn, the partnership between the National Observatory of Athens and the international network of 100 Resilient Cities for the provision of EXTREMA service was announced. This lead to development of the backbone of this emergency notification system for extreme temperatures.

Real-time condition updates during the ongoing extreme temperatures and heat waves could help prevent the consequences. EXTREMA is a tool that can spot-out in real time the city areas that suffer most during the ongoing event, indicating thus where the victims are to be expected. EXTREMA uses real-time satellite data and/or other model and city-specific data to estimate the temperature, humidity, and discomfort index for every square kilometer in the city. Temperature estimates are updated every five minutes, providing data at a spatial and temporal resolution that is not available from any other service. EXTREMA’s main objectives are to raise awareness, facilitate prevention, and protect health from the adverse effects of climate change.


EXTREMA Paris app features

EXTREMA Paris offers a range of features to the citizens and tourists at the city of Paris. Through this app, users can:

  • receive a personalized risk related to heat for their current location, and recommendations on measures to reduce their risk.
  • receive information, opening hours, and navigation information (by foot or public transportation) to the cool islands closest to their location.
  • create multiple user profiles. This is very useful when users want to check the risks of heat for their family members, specifically for their children and elderly. Users can enter their family members’ profile and their location and get the assessment of their risk related to heat.

In addition to the above mentioned features, the City of Paris through EXTREMA Dashboard can get real-time images and maps of extreme temperature hazard distribution in Paris. They also get a next day alert for expected extreme temperatures (based on meteoalarm.eu) to allow for proper respond and management of the cool islands. Through the Dashboard the City has now an information management tool that enables them to update the information on cool islands, including the ability to change opening hours, capacity, contact information, and add more centers in a particular area.


Replication potential

In addition to Paris, the cities of Athens and Rotterdam as well as the Island of Mallorca have also utilized EXTREMA services, making the start of an expanding network of EXTREMA cities as has proven to be a powerful platform where cities can learn from each other on how to best tackle heat waves as they happen. EXTREMA service is not exclusively for 100 Resilient Cities Network and a tailored app can be developed by EXTREMA team for any city around the world. Moreover, cities can learn from Paris and other cities in identifying cool islands and also locating new ones considering the proper spatial distribution of these centers around cities.

Climate Actors