I'll be lying down, sort of propped up on the bed--lots of pillows, cushions to keep me and secure me from falling to the side, don't want to block the tubing with my face, tubing entrance on the side secured with duct tape both in the bag and outside it at the entrance, so the tubing won't jar loose from the bag, Nitrogen must be kept flowing, elastic terry cloth sweat band around the neck, allowing some gas to escape-----Once you're unconscious, don't see how anyone can pull off the bag, doesn't happen in a hospital with anasthesia