She interviewed people from government departments, NGOs, and industry groups.
Some people had increased workloads, but for others workload problems had arisen due to clients presenting with more complex problems, or because staff members who had left had not been replaced.
"Workers are more likely to burn out in organisations where they experience lack of control over how they work, unreasonably tight regulations, and where they don't feel the organisation treats them with fairness and respect, or they feel disillusioned about the organisation's values," she said.
"In the aftermath of an ongoing major community crisis such as the earthquakes, people's capacity for work will be reduced.
"In this context it is foreseeable that workers will become exhausted and may ultimately suffer burnout unless organisations take proper account of that."
She said short breaks were helpful, but once people were burned out, it was essentially too late for minor measures.
When people were truly exhausted, Ms van Heugten said they lost their capacity for empathy, appear cynical, and tend to have a low self-esteem.
They were also likely to lose their attachment to the workplace, be less productive, and take more sick leave or ultimately resign.
Ms van Heugten found practical support, coupled with respectful empathic communication, went a long way in retaining loyalty.
She found people suffering stress needed to have fun in their life and exercise.
She said laughing at work was important, as was spending time with family and friends.