Parents are being told to send their children to school in the heatwave after a national emergency was declared.
Deputy prime minister Dominic Raab stressed it was “really important” that young children get the education they need.
England’s heat alert level will rise to red for the first time on Monday and Tuesday with temperatures possibly reaching 41C.
Rail networks have warned people to only travel if necessary on these days, more ambulance call handlers have been drafted in and people are being asked to look out for vulnerable neighbours.
However, No.10 has warned schools against closing because of the risk that unsupervised children could come to harm in the heat.
Asked if parents should keep children home for a couple of days, Raab told Sky News: “Look, we’re coming to the end of the school term anyway.
“But I think making sure young children get the education they need is really important, particularly after the pandemic, and the schools are well placed to deal with that.”
Raab also said people should be resilient enough to be able to “enjoy the sunshine” in the coming days.
He urged people to take “common sense” precautions, adding: “Obviously there is some common sense practical advice we are talking about – stay hydrated, stay out of the sun at the hottest times, wear sun cream – those sorts of things.
“We ought to enjoy the sunshine and actually we ought to be resilient enough through some of the pressures it will place.”
Asked if people should consider working from home, Raab said: “That is for employers to consider and people to decide.
“I’m not going to start dictating things like that. But obviously we have got more flexible working. So that will also help with this kind of thing.”
Ministers and officials met on Saturday as part the government’s emergency Cobra committee to discuss the national heatwave emergency.
Schools have been issued with guidance to enable them to remain open, with one official telling The Telegraph: “It is better for kids to be supervised in that sort of weather.
“There is a risk that if kids are off school they won’t be supervised and there is more risk they will come into contact with rivers and lakes and there are vulnerable kids who will be left completely alone.”
They also said schools should stay open so key workers would not have to stay at home to look after their children.
Cabinet office minister Kit Malthouse, who chaired the Cobra meeting, said transport services will face “significant disruption” on Monday and Tuesday and urged people not to travel.
Boris Johnson has been accused of going missing in action after he chose to skip the meeting and stayed at his Chequers country retreat, where he is due to hold a thank you party for supporters on Sunday.
Meteorologists have given an 80 per cent chance of the mercury topping the UK’s record temperature of 38.7C, set in Cambridge in 2019 – with the current heatwave set to peak on Tuesday.
Scorching temperatures are predicted for Monday, with Peterborough expected to hit 37C and Milton Keynes, Norwich and Lincoln thought to hit 36C – while temperatures could hit 40C in London on Tuesday.
The UK’s first red extreme heat warning has been issued across a large part of England from London to Manchester and York on Monday and Tuesday, while an amber warning initially covers all of England on Sunday and extends to southern Scotland and Wales from Monday until Tuesday.
The UK Health Security Agency has increased its heat health warning from level three to level four, which is described as a “national emergency”.