Many thousands of men are now returning from the front like Pavlo, with acute stress disorders associated with the sounds of drones, Dr Andriichenko said. The droneophobia can be triggered by an array of ordinary urban sounds – small motorcycles and scooters, lawnmowers, air conditioners – anything mechanical that whirrs.

The soldier was stranded in Siversk, northern Ukraine before comrades came up with an inventive plan to retrieve him