Publishing thesis as a book One of the answers here says that some researchers in humanities publish their thesis as a book. Could the same be done for example in physics, chemistry or math degree?  By book I mean the whole thesis, not just a handbook with selected material.  

And if it is possible - could the thesis on which you would defend your degree be written in a book format, i.e. be ready to go to the print shop immediately? Or do supervisors and reviewers expect the paper to be just a "big article" and having complete book in front of them would confuse them?
I also suppose that the book should not be printed(at least in many copies) prior achieving a degree, correct me if I am wrong.
Definitely don't print it before achieving your degree, in case you have to make major corrections (in which case the book would be a wasted expense).

In the UK, at least, it's usual for the final copy of a PhD thesis to be bound as a book - so in some respects, what you say about "ready to go to the print shop immediately" is already surpassed. However, that is not to say that the internal format of the work is that which would be expected for a normal book, and I imagine that this --- as well as perhaps writing to be accessible to a slightly wider audience --- is what is normally involved with somebody publishing their humanities thesis in book form.

The question that you perhaps need to ask yourself (or better explain to us) is: Why do you want to do this?