If returning to school after the holidays is stressful, imagine what it is like for teachers who never fully relaxed.
Calls to a helpline during the long summer break suggest that many school staff had difficulties escaping worries about work. The Teacher Support Network, which receives 17,000 calls each year, said it continued to receive queries during the summer holidays.
The charity has now published advice to help teachers "let go" of their work concerns during future breaks.
It suggests that teachers should lock away all of their school-related books and papers in a cupboard for the duration of the holidays. The guidance states: "Doing nothing is not an indulgence. It is your right and need as a whole person who happens to be a teacher."
Patrick Nash, chief executive of the Teacher Support Network, said it was impossible for the organisation to estimate the proportion of teachers who had problems relaxing during the holidays.
"Teachers call us saying they cannot understand why they don't feel well because they are on holiday," he said. "But there is a perfectly logical explanation - all the adrenaline that has been keeping them going during term-time has suddenly been removed."
Mr Nash said that teachers often ignored illnesses and stress during term-time because they did not want to take time off, particularly during the final few weeks before a holiday.
Teachers who did this often felt ill during their breaks, he said, and risked long-term health damage.
The network suggests that teachers should set strict boundaries on the time they spend working at home during the holidays and on the time they spend back in their schools if they visit to "tie up loose ends".
The charity also urges teachers to "try to rediscover interests and hobbies which have disappeared during the past year".
Professor Stephen Palmer, director of the Centre for Stress Management, said he was not surprised that school staff continued to feel under pressure during the holidays.
Previous studies had shown that 40 per cent of teachers suffered from high or extremely high levels of stress, compared to 20 per cent of workers in other professions, he said.
At the start of the holidays, teachers no longer had the same levels of adrenaline, but still had high levels of the stress hormone cortisol in their system.
Professor Palmer said teachers usually seemed to relax eventually during the holidays, even if it took extra time. "Walking along the beach in Cornwall this summer, I bumped into teachers who said that they have to take Prozac during term-time but don't need to when they are here," he said. "It is extremely sad."