Aiming this one at FlowerGirlPhysicist, but everyone else too. In relation to my question about how much helium would we need to fill a room with for a person to float, her response was basically "you'd die". Lol. "You could fill a room with X instead and find a giant balloon to climb into filled with air and you'd float in said balloon on said substance though."
I present to you giant balloons!