The Omnicom agency has about 250 employees.
"Jim set a precedent as soon as he came here of signalling to all of our team that when you're on holiday, you’re properly on holiday," says deputy chief executive Ali Gee.
"Jim expects that when you're on holiday, unless the world caves in, he won't be reading emails. [It is] really important for recuperating."
The agency's flexible working policy allows employees to work their contracted hours any time between 7am and 8pm.
In addition, all staff are encouraged to take up to two-and-a-half hours a week out for personal fitness, meaning that they can do so at convenient, non-peak times.
Senior staff, including Donaldson, get involved too.
Gee explains: "By setting that example from the top and enforcing it with a very overt policy, we're hoping that people will genuinely feel at liberty to do it."
FHF's monthly Boost 'wellness days' offer different clinics throughout the year, including sleep and mental fitness coaching, financial wellbeing, osteo and physio clinics, and nutrition.
Mental Health First Aiders are on hand for confidential conversations.
Gee says middle managers receive "very intensive training and coaching sessions" on getting a right balance between what "energises" and what "drains" a particular employee.
Annual appraisals have been replaced with "in-depth" monthly conversations to focus on this.
"We’ve found that one-to-one relationship with your direct line manager… actually drives a huge proportion of your sense of gratification with your job," she adds.
Meanwhile, FHF's Employee Assistance Programme offers 24/7 confidential support services for staff and their families, including access to counselling. The BUPA policy covers mental-health support services.
Gee says FHF's employee retention rates are "as low as it gets for big agencies – we're usually hovering sub-20" – while a staff survey shows a big rise in employee engagement. In addition, 85 per cent of leavers would recommend the agency as a place to work.
Data aside, she is convinced of the business benefit of focusing on mental wellbeing, saying bluntly: "We want staff that aren't burnt out, because burnt-out staff do crap work for clients."