Carol Berkenkotter gave me this advice 25 years ago and it is as true today as it was then. Writing a dissertation is emotionally and physically exhausting. I wrote mine in 48-hour chunks. My wife would take our nine month old to her parents and I would write nonstop all weekend. It got done, but I was a wreck. Beyond the wear and tear on your body, however, writing a dissertation requires an intellectual narrowing of focus that makes it hard to think about anything else. So teach your classes well, get something in the mail, and give yourself time to heal.