I have a thin skin system, and I would not wear it more than four days. Just think about it for two seconds. Your scalp is full of sweat glands. If your outside on a hot day, you are going to sweat right? Now just look at the thin skin material. It is non porous, air nor water can get inside. That plastic is going to be firmly on your head, ur scalp will not breath. Now maybe for those in these salons, they are not as aware of it because their heads are completely slathered with glue in a full head bond. So the glue is probably clogging all their pores or something. then they saturate their scalps with alcohol to get the bond removed and the alcohol starts killing all the built up bacteria so they might not notice a smell . But me personally, I wouldnt want glue and plastic on my scalp for that long. I just think that is very unsanitary. I mean would u want to wear plastic socks for that long?