An upcoming summer holiday can be an extra source of stress. There’s work that should be done in advance, and you’ll have to make up for lost time when you’re back – not exactly ideal conditions for relaxation. How can employees start their long-awaited break as stress-free as possible, and then carry a positive mood long into their return to the workplace? It starts with pre-holiday planning, says Nicole Ottersböck, a social scientist at the Düsseldorf-based Institute of Applied Industrial Engineering and Ergonomics (ifaa). She advises notifying colleagues and/or customers/clients of your pla…