HBOT is simply not a miracle treatment, and the FDA is pretty clear that it shouldn't be used to replace any medical treatment. "FDA is concerned that some claims made by treatment centres using HBOT may give consumers a wrong impression that could ultimately endanger their health," the organization wrote in a 2013 statement . In some cases, the HBOT could slow recovery or pose health risks, such as ear injuries and lung collapse, according to the Mayo Clinic . (Not to mention, some people experience claustrophobia inside the tubes.) And although Bieber shared that he was sleeping inside of his chamber, the devices should really only be used for one to two hours at a time, in a healthcare setting, and with a doctor present to monitor.