As the UK enters peak summer holiday season, hidden pressures at work are building in ways that may not become visible until later in the year. New research from Timetastic, the UK’s leading staff holiday planner, shows a marked increase in sick leave during the final quarter, with October, November, and December seeing up to 20% more absences than other months. The findings point to a connection between summer holiday cover and end-of-year burnout, suggesting that workers who absorb additional responsibilities during the summer months may face delayed health impacts.
“We typically associate illness with colder weather, but our data paints a different picture,” said Oliver Higenbottam, managing director at Timetastic. “An additional driver may be the stress caused by working through summer when others are off. Juggling unfamiliar responsibilities, extra workload, and limited support has a slow burn effect that catches up with people by the end of the year.”
The Health and Safety Executive defines stress as “the adverse reaction people have to excessive pressures or other types of demand placed on them.” This reflects what many employees face in workplaces operating with fewer staff during the summer period. According to Timetastic’s research, the cumulative pressure of additional tasks, unclear responsibilities, difficult conditions, and a lack of support contributes to rising stress.
Too many or conflicting demands often leave employees balancing multiple roles. Unfamiliar tasks can lead to confusion and anxiety when there is no clear guidance. Poor conditions, such as overheated and poorly ventilated offices, increase fatigue. Deadlines and rigid schedules limit employees’ control over their work. When key team members are away, decisions are delayed and support is harder to access. Workers are often underprepared due to insufficient training for temporary responsibilities.
“We’ve heard time and time again from businesses that they rely heavily on a handful of people to hold things together when the rest of the team is away,” said Higenbottam. “It’s no wonder we see the consequences of that pressure play out in the months that follow.”
Pressures are not limited to the workplace. Families face challenges such as childcare demands during school holidays, financial strain from summer spending, and disrupted routines that interfere with sleep and recovery. These factors intensify existing stress and contribute to a pattern of fatigue and increased sick leave later in the year.
Timetastic’s research challenges the assumption that autumn absences are caused solely by seasonal illness. While cold and flu rates do increase in winter, the data points to a different factor. A 2024 report from Breathe found that 65% of UK workers do not use their full holiday entitlement, often due to workload pressure. This trend adds to the risk of burnout.
With employee well-being gaining attention, businesses are being encouraged to take proactive steps. Planning annual leave more effectively, maintaining communication, and offering support during the summer months can ease the burden on those covering for others. Providing training for temporary responsibilities and ensuring managerial guidance is available may also reduce stress and help staff feel more prepared.
“Sick leave isn’t just about catching a cold,” said Higenbottam. “It’s often a warning sign of deeper, unaddressed stress. Businesses that want to support their teams and maintain resilience into Q4 should be looking now at how to lighten the load, offer clarity, and provide better support, especially for those holding the fort during summer.”
By preparing ahead and addressing these issues, employers can reduce the impact of summer stress and support a healthier workforce through the rest of the year.
