It may not be an issue in America but over here in the UK I make sure that anyone who takes a kitten from me knows to block the fireplace off or has a fireguard if they use the fire. I've had first-hand experience of a kitten running up the chimney and being out of reach. Lola did it the day we brought her home!!
I would clean all little toys up for a while, it seems everything interest them and is fair game.
