Four in 10 office workers and small business owners are highly stressed in their job, with Monday mornings being the most stressful time for many, a new study has found.

As part of the study, several hundred workers were surveyed about stress, while the body temperatures of a group of volunteers were also taken at set times over a five-day period.

The temperature results showed that four in 10 workers had a stress temperature of 18-24 Celsius. This indicates that they are highly stressed or are suffering from anxiety.

The most stressful time of the week was found to be first thing on a Monday morning, with almost six in 10 people showing signs of stress at this time. The second most stressful time of the week was Monday evening.

Friday was also found to be one of the most stressful days of the week. The least stressful day was Wednesday, with just one in three people recording signs of stress then.

Meanwhile, the survey of workers revealed that at least one in four people feel stressed about their job on a daily basis, while almost half believe that work stress affects their health.

One in three admitted to comfort eating in an attempt to deal with their stress.

Almost half said that they work unpaid overtime, but one in five of these said this is because they are afraid of losing their job otherwise.

According to Neil Shah, who conducted the Stress At Work study on behalf of Viking office supplies, the results show that many people are dangerously stressed, but they may not even be aware of this.

"Tension and stress can manifest themselves in many different ways, but can be linked to long-term health problems such as headaches, heart problems and depression.

"From a business point of view a stress free worker is a more productive, proactive and valuable one. Ensuring really simple things like people taking a lunch break or doing exercises in the office can make a huge difference," he said.