What is the Red Baron wearing?

[jluetjen]

I just came across this interesting speed adjusted video of Manfred von Richthofen. I noticed that at 0:57 and other places you can see what appears to be a cord that goes vertically around his head. I assumed it to be holding his hat on for the upcoming car ride. Such cords were not unheard of in caps of that time. But then at 1:55 it reappears while he's dressing to go up in his drei-decker -- at which point he takes the hat off and the cord remains. I was confused.

Is it by chance holding the bandage on from his head wound? In the scene with the airplane, you briefly see the left side of his head prior to taking off his cap, and there is what appears to be a white dressing of some sort under his hat.

What do you think?