The cold spell has just hit Western Europe and has already been raging for several weeks in the East. It particularly threatens migrants trying to reach the Schengen area. Adrien Selbert went to Belgrade where nearly a thousand migrants are surviving in an abandoned industrial brownfield behind the train station of the Serbian capital. At -20°C, huddled together for warmth and with only blankets and a wood fire, living conditions are well below the threshold of dignity. While the Balkan road has been closed since March 2016, some people still try to cross into Hungary from Serbia and are violently repressed. The Hungarian government has decided to fortify its southern border. It is believed that the Iron Curtain will return. Snow has been covering the Serbian capital since the beginning of January and keeps falling. In Belgrade, thousands of men fleeing war-torn countries are destitute and try to survive in the polar cold. While most of the women live in overcrowded official camps, the men are forced to find shelter in disused factories. They had no toilet or shower, and used a hose and wood-heated barrels to wash themselves. An association allows them to have one meal a day, no more. Inside the plant, the mercury does not exceed zero degrees. On the facades, graffiti made by men call for help. The smoke causes respiratory problems, asthma and bronchitis. For these Afghan and Pakistani immigrants, skin problems and cold-related injuries are multiplying.