Many people need to lay down as they can't sit in a vertical chamber for 2 hours in a chair. Although 1 in 4 people who get a chamber from me get a vertical chamber, many people have positional intolerance. Some people can't sit for 1 hour. The majority of the people prefer to lay down, especially if they are going to be in there for hours. The newest trends for laying down in the chamber are vibro accoustical mats (highly recommended for those with sensory issues), and waterbed chambers. Many people are putting a waterbed bladder in their chamber. Having 2 vibro accoustical speakers underneath the water mattress sends the sound waves through the water and the entire body feels it. It is the best experience of all in a hyperbaric chamber. Having the biomat makes it even better.
Note: I use a Richway Quantum Cushion if I am not using the waterbed bladder. I carry these cushions for those who need them.
Depending on the size of the chamber, the infrared mat may be able to go inside the chamber and the vibro accoustical speaker instead of it going under the chamber. If interested in reviewing different protocols to use with orizontal chambers, let me know on my Hyperbaric Chamber quiz.