The first what I thought was a flashback turned out to be a severe panic attack from what I was told. I sat in the middle of my room and rocked myself until I could handle everything again...scarey. I was told to wear a rubber band on my wrist and if I started feeling this again to give it a big snap, more if needed...ouch. I haven't had many, tried the band, worked sometimes but usually go internal and rock and sing James Brown's, I Feel Good song. That works for me......Out of body, strongest one was from a drug overdose...no control there. I have meditated and intentionally left. Prevention, not sure, a key word or phrase??? Hopefully better informed people will chime in.