Sorry, that I just know the German name, it is called a “Rechteckmantel” which basically translates to rectangular cloak. It was worn from the bronze age into early medieval times in Europe. It is basically as others pointed out just a rectangular piece of wool fabric, much like a blanket. It can be used as such when travelling.

The “Rechteckmantel” used to be closed with a brooch or a pin and could be worn in various ways. The one in the picture for example is of someone who expects to have to use their right arm for working or drawing a weapon. But one could also close the cloak in the front with a bit more overlap for more warmth but that would limit movement by a lot.

It is a very comfortable piece of clothing. I have a hobbyist interest in living history and my “Rechteckmantel” served me well during many cold nights.

As far as I know: forget this thing about the lowered metabolism. Your body needs the energy it needs for basic functionality.

You may feel less active, lowering the energy used above the basics, but still your heart, lungs, brain, temperature management and all the other stuff need roughly the same energy. If your body does not get it from food then it will use up the fat.

But eating this low level of calories you must make sure that you consume all needed vitamins, minerals and enough protein.

And being less active may end up in a decline of muscle mass. In the end that may lead to lower basal metabolsk hastighet, but not your metabolism shutting down.