The very first night I slept on mine(I've long since left it behind) I'd set it to 100 and passed out( been drinking ) on my right side,I woke up in the middle of the night to use the bathroom, took one step and collapsed to the floor staring up at the snow on the TV as my entire right side of my body was numb,I remember thinking I must've had a stroke or something in my sleep and this was what the rest of my life was going to be like
anyway I made a forced conscience effort to try and move my right hand fingers and they started to wiggle, idid the same with the right foot,I'm thinking I'm gonna come out of this,as it was just numb and tingling
apparently I'd pinched a nerve or whatever to have made pretty much my entire right side of my body to go to sleep,,, needless to say ,the 100 sleep setting was not for me,pretty sure I'd settled around 45 after that,,,, I agree with the above poster who has the degenerating disc back problem, same here and that air mattress along with quality insoles in the work boots seemed to help ,as before that I tended to have my back flair up in pretty pain on me about twice a year with each incident lasting about 6 months each
( before buying it, I was regretting calling them on the phone as they were incessant in their approach of making a sale,,,it was around $1,600 iirc)