Ohhhh brilliant idea! But doesn’t the yarn scratch a bit? I am not sure if you remember my fake brioche scarf from last year in this neon green. The yarn also had a reflective thread in it and I stopped knitting it, because it scratched on my neck when I tried it on.
Perhaps, I will unravel the scarf and use the yarn for a hat and sew some fabric inside (I love to run in the evening and you are right it’s so fast dark)
My kids have not complained, but they have thick hair. If I used the yarn for someone without much hair, I might just do some duplicate stitch on the surface in the reflective thread.