A couple use the Carboniferous Room Portable in the back yard of the Love Hotel. They are sharing a carboniferous atmosphere which is 35% oxygen, with a slightly higher atmospheric pressure and with a s smell mixture of some ferns and swamp.

Male user inside the Carboniferous Room Portable.

Female user inside the Carboniferous Room Portable.

This graph shows the change of oxygen and carbon dioxide over geological time. The carboniferous period is the oldest period in history in which humans would be able to survive without additional life support machinery.