This phenomenon contributes to the spread of fire and the creation of secondary sources. This also makes it difficult to predict a fire’s trajectory, making it even more difficult for firefighters to intervene.
Published 07/22/2026 12:24
Updated 07/22/2026, 18:52.
Reading time: 2 min.
Fire in Cotignac (Var), July 22, 2026. (THIBAUD MORITZ/AFP)
Fires are multiplying and spreading at tremendous speed. The spread of these fires, accelerated by extreme heat and drought, is also exacerbated by the phenomenon of fire surges. On Sunday, July 19, a fire that started in Tarado (Var) actually experienced significant “waves” that reached the gates of the neighboring town of Arc-sur-Argens.
Two firefighters died in their truck near Bordeaux on Tuesday “trap” by the flame. Their death occurred “in the first minutes of the attack phase” fire. This fire spread from top to top “with numerous fluctuations. (…) Accompanied by a changeable wind, the situation was very unfavorable”“said Marc Vermeulen, director of the departmental fire and rescue service (Sdis) of the Gironde. The official described the flames as 20 to 30 meters high.
About 2,500 hectares were also engulfed in fire between Tuesday and Wednesday in Var. Franceinfo explains to you what these “waves of fire” are, which worsen the spread of a fire and make it difficult for firefighters to intervene.
Fires can be spread by several phenomena, including projection, i.e. “fire swing” Eric Brocardie, a spokesman for the National Federation of Firefighters, explained to franceinfo. Belonging “Brandons” pieces of burning bark or flaming ash from the original fire may actually pass through “from a few meters to several hundred meters or even several kilometers” etc. thereby contributing “spread of fire through the emergence of secondary sources”, described in detail in a document from Sdis de la Loire.
“The closer we get to the south of France, the more often natural disasters occur due to sudden fires,” Eric Brocardi clarifies. The vegetation of this geographical region, where there are many pine forests, actually contributes to this phenomenon. “During a fire, pine cones absorb a lot of gas and turn into red-hot projectiles. There is a rocket effect.”– explains a representative of the fire brigade.
Fire swings can also be “related to the ash present within the smoke”– he recalls. With the wind these “hot particles settle further” and could cause another fire, he says.
This phenomenon, which accelerates the spread of fire and creates secondary outbreaks, complicates the work of firefighters. Fire swings actually make fires worse “difficult to control” Eric Brocard says. They actually do “makes it more difficult to recognize a fire and complicates the operational strategy that must be implemented to try to contain it quickly,” he explains.
Intervention, “You’ll think you were keeping the fire going. And then you turn around and the fire has actually spread 100 meters further.” illustrated by Eric Brocardi. However, there is a method to prevent the development of a fire by rocking. Firefighters can really place “cars (…) in the array, on the opposite side of the fire, in order to intervene faster”describes the French Forest Observatory in detail on its website.