2.3.2. Sham-Pajamas Group
FIR-pajamas
To control for the placebo effect in the FIR-pajamas group, subjects in the sham-pajamas group received two sets of pajamas with identical physical appearances that were produced using the same fabrication process as the pajamas received by the FIR-pajamas group. The sham pajamas were made of pure cotton fibers and handmade fibers without the FIR-emitting function. The subjects were asked to wear the sham pajamas daily at night for six consecutive weeks.