## 1 Introduction  
Forest fires are one of the most common and, at the same time, serious emergencies facing humanity. They threaten not only natural areas, where they cause important losses of plant and animal diversity, but also urban areas, where they can cause dramatic human and material losses. Furthermore, forest fires cause significant emissions of greenhouse gases and consequently are contributing to global warming. For these and other reasons, states develop policies for fire prevention, early detection, and rapid intervention.  
Quantifying the fires and their consequences along the world is not a trivial task. According to the World Fire Statistics [1], a report published by the International Association of Fire and Rescue Services that collects data from multiple governments, there were 4.5 million fires and 30,800 deaths in countries with 2700 million inhabitants in 2018, which means 1.7 fires per 1000 and 1.1 deaths per 100,000 inhabitants that year. Although these figures do not take into account the whole world, they allow us to quantify the magnitude of the problem. The information provided by several space agencies supports this thesis: the European Space Agency (ESA) publishes the World Fire Atlas with the information collected by ATSR-2 [2] and Sentinel-3 [3]), whereas the National Aeronautics and Space Administration (NASA) does the same with the Global Fire Atlas [4].  
Current forest firefighting missions consider prevention, surveillance, and extinguishing tasks. The first ones seek to prevent the occurrence of fires and limit their consequences, the second ones look for detecting fires early, and the third ones search to put them out quickly and safely. Firefighters reveal the lack of human and material means and the degraded information of the scenario as the main problems in these tasks. They routinely use multiple types of vehicles and machinery to improve the performance and safety of these operations. However, the use of robots and especially drones is not common, although these autonomous systems could solve some of the current challenges.  
This paper aims at analyzing the current problems in forest firefighting missions and the potential of robotic technologies to solve them. Therefore, we pose the following two research questions:  
1. What are the main problems in current forest firefighting missions?
2. How can robotic technologies contribute to solving them?  
For this purpose, the paper analyzes the data provided by governments, the results of two original surveys on firefighters, and the literature on robotics applied to forest firefighting.  
Finally, the paper proposes a concept of operation for the application of drone swarms to fire prevention, surveillance, and extinguishing tasks.  
The remainder of the paper is organized as follows: Section 2 addresses the current situation of firefighting, analyzing the public statistics provided by multiple countries and presenting the results of our surveys and interviews to professionals. Section 3 collects various works developed in the context of academy and industry that apply robots to firefighting tasks. The concept of operations using drone swarms to support firefighters in all these tasks is presented in Section 4. Finally, the main conclusions of the work are summarized in Section 5.