It was purportedly (and probably in actuality) intended as a survival aid to be used after landings and before recovery in the Siberian wilderness, although allegedly was intended as a defensive weapon against in-space attacks by the US space program.
I think every astronaut that embarked in the Soyuz spacecraft had to go through a wilderness survival training.
I know the french astronaut Thomas Pesquet had to survive a week in Siberian first in winter before embarking on the Soyuz.