Burn-out has become an ubiquitious word in the workplace esp after IT rev.One needs to know how much they should slog.They should take care of their health.Moreover a sojourn break from work gives them an energy to finish the work.Continous slogging over time will certainly detoriate one's health.Proper planning will avoid those Burn-out.You may check burn-out by decreasing levels of energy in one's work.When you feel more industrious then its time to take-off.
-Deepak.