Go to sleep in your own body and wake up in someone elses, then live a completely different life to your own, surrounded by strangers and in a foreign place, maybe even a foreign language too....and see how you feel.

Then get used to seeing another person staring back at you in the mirror, get used to having a voice that is different, or perhaps get used to having a different gender...maybe calling a stranger your wife and pretend to have a relationship with them until you can't take the guilt of it all and tell them the truth, or simply leave them.

Get used to being unable to commiserate with people about how much more heavy/short/less mobile/ugly/different your new body is or how you are missing your friends and family back 'home.' Then maybe you could grieve for the people you once knew after you meet up with your "real" family and find nothing but disbelief and rejection in their eyes.

I think it has a VERY big emotional and physical impact regardless of whether it is planned or not. It takes a very strong person to adapt to a soul exchange on any level.

I've done it a few times and I was barely ready even after I prepared for it as much as I possibly could.