If the premise of the job is a pressure cooker in itself, then getting feedbacks from the ground for a better method of working for them to keep themselves motivated and make the job a little more tolerable/enjoyable while keeping the productivity up.
There are so many factors that people get stressed up about. Unless we know the full details of your company inner working/industry, the frequent complaints and problems that you face with your employee, pretty much everything replied will be wild guesses which will not be a fruitful discussion.