This is a ridiculous warning, but..

Polyfil is very slippery on smooth floors.

I was playing around with my digitigrade leg padding with some loosely stuffed in to fill it out, and started doing a little dance. Some of the stuffing came out and got scattered on the floor, but I ignored it since it's stuffing, it can't hurt you, right?

One moment I was dancing, the next moment I saw sparkles and faceplanted into the floor, right on my chin. I ended up needing four stitches because I slipped on polyfil. Don't leave loose stuffing lying around on the floor where you might slip on it and end up like me :/