Do one get healthier by going on vacation???

Yes I think you do. It also depends on where you vacation to and where you normally live. A few years ago I had taken a vacation for a week and when I came back to the city I was living in at that time I got very sick for a few weeks. I noticed that happened everytime I'd go on vacation, so after a few times I went to my doctor who figured out the problem. I was allergic to the air of the city I was living in, becaue of the high pollution, so whenever I would leave, my body would get used to cleaner air and upon arriving back in the polluted air city my allergies would act up like crazy. I think part of it too is that generally when one is one vacation, you're a lot more relaxed and don't have your work or daily life stress to worry about.

Well, I am not sure if you necessarily become healthier. But, I think that like how you feel...you are more refreshed, and not as stressed out. I think that is what makes you feel like you or others are "healthier". I environment usually changes and so does the situation around you, so when you come back, it is a refreshing feeling! :D