Britain has been hit by a heatwave this week, with people flocking to parks and beaches to enjoy the sun.
As temperatures rocket up to 33C, parents may be wondering how hot it has to be for schools to close and pupils to be sent home.
Schools follow the same rules as workplaces, specifying a lower limit but no maximum.
The National Union of Teachers has guidelines for schools in a heatwave, Birmingham Live reports.
Temperatures should be “reasonable” with “clean, fresh air”, so staff could open windows or doors, but it does not necessarily mean they will have to close the school altogether.
Schools’ Health and Safety Executive says: “During working hours, the temperature in all workplaces inside buildings shall be reasonable.”
Leaders and teachers are urged to roll out steps for children who feel uncomfortable amid the stifling heat.
For example, pupils should be allowed to relax their uniforms, the NUT says.
The school should also roll out any steps they see fit which could help combat temperatures in classrooms.
The NUT advises: “If in doubt, 26C should be used as the trigger for these measures.
“Other steps may also need to considered such as closing classrooms which are unacceptably hot and teaching classes elsewhere, or even sending pupils home, provided reasonable notice has been given to parents.”
Kids were sent home in 2006 during the UK heatwave, as temperatures hit 36C in some areas.
Chris Keates, NASUWT general secretary said: “Schools should ensure there is an easily accessible source of drinking water available for both staff and students and consider operating flexible working arrangements, where possible, to avoid using classrooms particularly susceptible to high temperatures during the hottest hours of the day.
“If temperatures exceed sensible limits, then schools should undertake a risk assessment and put in place measures to tackle the issue, which could include the use of blinds, fans or additional cooling/heating.
“Where appropriate, employers should also provide alternative rooms or, in extreme situations, order the partial or total closure of the building. Adequate ventilation is also critical, particularly in classrooms used for subjects such as technology, where dust may be generated. Legally, classrooms must be capable of being ventilated adequately.”
Parents should also make sure their kids are well-equipped during a heatwave, with a hat and sunscreen if they are likely to spend time outdoors.
It comes as a restaurant in Wales announced it would close for three days to keep staff safe during the heatwave.
The owners of The Stone Crab in Saundersfoot, Pembrokeshire, Wales, decided to close after the Met Office issued an Extreme Heat Warning for the first time ever until midnight on Thursday.
The warning covers a large part of Wales, all of southwest England and parts of southern and central England.