A couple of my favorite visors pinched behind my ears and, after a while, gave me a headache. Rather than throw them away, I decided to try a last effort. I heated my oven to 300 degrees F and put the visors one at a time on a pan. After 5 minutes, I removed it. Since it was very warm, I used pot holders. As it seemed more pliable than before, I slid it down over the back of my recliner. It was just enough wider to open it up so it didn't squeeze my head.
I left it there until it was cool. It worked so well, I repeated it with the second one. I melted the bill on one because I had the oven too warm at 350 degrees F. So you might want to try 250 to 300 degrees F first and check after 5 minutes.
By Ann from Loup City, NE
I may try that on one of my tight plastic headbands.