Winter can be a difficult time in terms of stress, since the shorter days can lead to darker moods among employees.
This is the view of Dr Lance Workman, senior lecturer in psychology at Bath Spa University, who suggested people can get lethargic or even depressed as a result of not seeing as much daylight.
"I think one of the things we do know which is quite well established is that as the day shortens for a lot of people the amount of serotonin we produce begins to fall," he said.
Dr Workman urged those who are struggling with their mood during the winter months to take some exercise while it is bright outside, as it can make a "huge" impact.
Research by Kellogg's showed that one in ten workers in the UK does not see any natural light during their working day, which has led the company to introduce a flexible schedule for its employees.
