Schools are undertaking measures such as closing early, allowing pupils to wear PE kit or rescheduling sports days to cope with rising temperatures next week.

The Met Office has issued an “amber” warning for heat on Sunday, Monday and Tuesday, stating that this could pose a danger to life, while temperatures may exceed the 2019 record of 38.7C.

Schools have relaxed uniform rules and adjusted timetables in order to cope with the heat.

St John’s CE Middle School Academy in Bromsgrove has said pupils “can come to school wearing non-uniform to enable children to wear loose, light-coloured clothing that will help keep them as cool as possible”.

The school said it would sell ice pops to pupils in aid of Cancer Research, and that pupils would be encouraged not to run during playtimes to prevent heat exhaustion.

The Hereford Academy in the West Midlands is allowing secondary school pupils to start early next week and finish at 2pm to allow them to be “away for the hottest part of the day”.

The academy said it would also bring its sports day forward to avoid the high temperatures next week.

Clapton Girls’ Academy in east London will also be sending pupils home at 12.30pm on Monday and Tuesday.

Headteacher Anna Feltham wrote to parents to say: “Already, many classrooms are very hot, even with fans, and students are struggling to keep cool, drink enough water and maintain concentration in lessons.”

At the Co-op Academy Swinton in Greater Manchester, pupils are being permitted to wear their PE kit rather than uniform on Monday and Tuesday, as a “temporary adjustment to the requirements for uniform”.

Arnold Hill Spencer Academy in Nottingham said pupils will have the option to wear their PE kit instead of their normal uniform, while pupils preferring to wear uniform will not need to wear a blazer or tie on Monday or Tuesday.

Great Dunham Primary in Norfolk also advised that all pupils should “wear PE kits rather than uniform on Monday and Tuesday”.

The school added: “Please ensure they have a sunhat, lotion and water bottles. We will not be going out at lunchtime, instead the children will eat and do activities in class. Stay safe.”

Abercarn Primary School in Newport also said that pupils should apply sunscreen, wear a cap or hat and bring a water bottle to school, while pupils can wear non-uniform from Monday to Wednesday next week.

At Finham Park School in Coventry, pupils will be allowed to wear PE kit on Monday and non-uniform on Tuesday and Wednesday.

Students at Houlton School in Warwickshire have also been told that they will be able to wear the school PE kit in lieu of their uniforms from Monday to Wednesday.

In a letter to parents, the school’s principal added that “pupils do not need to be outside at any time if they do not wish to be” during the extreme weather.

In the West Midlands, where temperatures up to 37 degrees are expected next week, Oldbury’s Rounds Green Primary School will allow children to wear “loose and comfortable” non-uniform on Monday and Tuesday.

Andy Byers, headteacher of Framwellgate School Durham, said he would be encouraging pupils to drink water and wear sunscreen and pupils would come to school in PE kit.

“We’ve got a sports day, we’re going ahead with it, but we’re making sure that we’ve got measures in place, risk assessments in place to do it,” he said.

In an update to schools on Thursday, the Government signposted heatwave guidance for teachers and other early years professionals, noting that children sweat less than adults and cannot regulate their body temperature as well, which puts them at risk of heat stress and exhaustion.

During heatwaves, teachers are advised to encourage pupils to wear loose clothing and sunhats “with wide brims”.

Staff should open windows as early as possible before pupils arrive in the morning to improve ventilation and should keep the use of electric light and equipment to a minimum.

Mechanical fans can be used when temperatures are below 35C but not at higher temperatures as they can make dehydration worse.

The Government warned that pupils with heat stress “may seem out of character and show signs of discomfort and irritability”, while signs of heat exhaustion can include tiredness, nausea and confusion.