The vapour fills the room, so no matter where it is in the room I feel it is effective. It’s not so noticeable when you’re sitting in the vaporised room but when you walk out then back in again you can definitely smell the difference.

I always put mine in the room a couple of metres away from the cot. Make sure there is nothing around it and keep an eye on it. I’ve never had a problem except for condensation on the windows which you can wipe away later on