In the movie Pokemon Ranger and the Temple of the Sea, Ash does switch bodies. Ash and the pokemon ranger, Jackie, switched bodies because Manaphy used one of its special powers called Heart Swap, which causes two or more people to switch bodies. I think that the effects are temporary. Ash and Jackie both agreed that the switching body experience was wierd. For more information on the movie, you can go here: http://en.wikipedia.org/wiki/Pok%C3%A9mo… I hope that this helps.