All of your staff members have an energy bar that slowly decrease as they perform their job. Once their energy reaches zero, they will stop working and go on a break.

Staff members also have a happiness bar that can decrease over time. If a staff member is unhappy, it will impact their performance - they will receive a penalty to theis stats. A staff member can recover happiness by resting in a staff room.

Staff members can rest by walking around, or in a staff room, if an available staff room exists. Resting in a staff room takes less time, and increases staff member happiness.

During their break, they will not perform any task, and patients will wait near the room for the break to finish.

You can also manually increase a single staff member's energy and happiness by giving them a medical booster.