People talk about burnout at work as if it's caused by spending too much time doing high stress tasks or in a high stress environment. It is not. That is exhausting, but is not burnout. If it were, doctors, firefighters, teachers and others in these types of environments would be burned out all the time.
Burnout is doing work that has no meaning to you personally. People burn out even in low-stress jobs completed in 8 hour days. I've been overworked and I've been burned out. Burnout is a much worse experience and to be avoided at all costs. Overwork is life for most people trying to do something truly great. That's why there are vacations.
Vacations don't cure burnout yet many people expect them to. If you do work that to you has no value, you will be just as burned out when you return to that work from vacation as you were when you left it.
There are two cures: either redesign your job or get a different one.