Parents have been warned about the threat of asthma attacks when their children return to school.
Asthma UK fears for the 1.1 million children with the condition in Britain after a worrying increase in hospital admissions after summer holidays.
More children in England are taken to hospital after an asthma attack in the middle of September than any other period in the year. More than 4.6 times as many children needed hospital treatment in the third week of September 2011 than six weeks earlier.
Six and seven-year-olds are the most likely to be rushed to hospital with an asthma-related problem at the start of a new school year.
Asthma UK aims to combat the issue through a campaign to raise awareness. The charity said parents can help children avoid an attack after the summer break by ensuring they take their preventer inhalers two times a day while they are off.
Research suggests children who do not keep up with their medication are in more danger of suffering a serious asthma attack when they come into contact with colds, flu and stress in the classroom.
Asthma UK deputy chief executive Dr Samantha Walker said: "Normal routines can go out of the window during the summer break, which can effectively create a time-bomb for children with asthma.
"Those who forget to take their preventer inhalers over the summer will be less in control of their symptoms and therefore more vulnerable to asthma attacks come term-time."
Copyright Press Association 2013