But not all outdoor work has come to a complete standstill. “There is always something to do for roofers in frost,” says roofer Sander Hermans. He can work on flat roofs, which is not dangerous. But kittens, for example, are more difficult. The freezing cold makes the sealant stick less well. Yet Hermans continues to work, because after the rainy period of recent weeks it is extremely busy for roofers, perhaps too busy. “I look at the mailbox with tears in my eyes,” says Hermans.