Burnout results in people feeling a lack of fulfillment from work. They don't feel like they are accomplishing anything. Take stock of your personal accomplishments every day, big or small, and you will start finding meaning in your work, a recipe to avoid burnout.
Switching back and forth between chat and other work consistently can lead to more work and a lack of efficiency in the long run. How we communicate is important to build trust and show that we value the work of our employees.