Businesses trying to improve their absence management may have noticed an increase in the number of workers calling in sick during the recent heatwave in the UK, new research suggests.

A survey by PMI Health Group found that almost one in three (30 per cent) companies have experienced an increase in absence rates since the beginning of the summer.

Despite this, more than half (54 per cent) of employers do not operate flexible working systems that can be put into practice at short notice, according to the study.

PMI Health Group director Mike Blake said it was not necessarily a surprise to find that workers are more likely to take time off during periods of warm weather.

He urged organisations to look at whether this trend is caused by genuine illness or by lifestyle factors, and to consider the potential advantages of taking a more flexible approach to working hours and benefits packages.

"Flexible shift patterns will allow employees to fulfil their required hours without feeling their work-life balance is compromised, while holistic wellbeing schemes can work on improving workplace morale," said Mr Blake.

Almost three-quarters (71 per cent) of the surveyed companies said it is easier to engage staff in wellbeing programmes during the summer.

Mr Blake pointed out that there are a number of ways for businesses to encourage their employees to be more healthy and active, some of which could require substantial investment.

"Onsite leisure facilities or fitness classes represent a good option for businesses that can accommodate them," he said. "Whether fully or partially subsidised for staff, these benefits are exempt from tax and national insurance contributions."

Other options include discount gym memberships and financial incentives for people who engage in regular physical activity.

The Confederation of British Industry released figures last month showing that work absence costs the UK economy £14 billion a year, despite being at a record low.