This never happened with my daughter, but since my son appears to be doing it on purpose, figured I'd give y'all a heads up.

Lately when I pick up my son to remove him from a situation (like if he's playing with the sink and I want to take him out of the bathroom, or he's climbing up onto the table), he will throw his head back as hard and as far as he can, often slamming it into my face if I don't hold him far away enough. Feels like a punch in the face. Doesn't seem to happen as much if I hold him facing me, or of course if I hold him at literal arm's length, his head can't get me.

I know I'm not the only one with a little grump! Good luck! Watch your face!