A warning has been issued by the Met Office over fears that the expected heatwave will have a significant impact on health.
This weekend is set to bring the hottest day of the year so far, with weather experts predicting temperatures will reach a sizzling 31C (87.8F) tomorrow.
The mercury will begin to creep up to the high-20s today before spiking at the record tomorrow.
The continued hot spell shows no sign of ending as temperatures settle around the mid-20s well into next week.
A Level 2 Heat Health Alert has been issued by the Met Office for parts of England.
A spokesman for Public Health England (PHE) said: “Level 2 alerts are triggered as soon as the Met Office forecasts that there is a 60% chance of temperatures being high enough on at least two consecutive days to have a significant effect on health.
“This will normally happen two to three days before a heatwave is expected to occur. As most deaths occur in the first two days, this is an important stage at which to ensure readiness and swift action to reduce harm from a potential heatwave.”
The areas affected by the alert are Yorkshire and the Humber, East Midlands, East of England, south-east England, London and south-west England.
The Met Office alert warned of heatwave conditions today and tomorrow.
“Heatwaves can be dangerous, especially for the very young, very old or those with chronic diseases,” the alert said.
Dr Angie Bone, head of the PHE’s Heatwave Plan, said: “Everyone can enjoy the sun safely by keeping out of the heat at the hottest time of the day, avoiding sunburn and staying hydrated with plenty of cool drinks.
“The elderly and those with long-term illnesses are particularly vulnerable to the effects of very hot weather, so it’s important to look out for them and keep indoor areas as cool as possible.”
Tom Tobler, a forecaster with MeteoGroup, the weather division of the Press Association, said tomorrow’s weather is very likely to beat the current record of 29.7C (85.5F) reached in Bournemouth last Sunday.
“It’s certainly going to be a very hot weekend with lots of sunshine,” he said.
“Temperatures are predicted to reach at least 31C (87.8F) on Saturday, which will make it the hottest day of the year so far.
“Temperatures will drop a few degrees on Sunday into next week but we can’t see any sign of the hot weather changing over the next week.
“It’s been a very hot start to July, and it’s likely to last a while longer, for the next one or two weeks.”
The North of the UK has seen the best temperatures over the last few days, with the highest recording of 28.8C (83.8F) in Castlederg, Northern Ireland, yesterday.
But the heat will now start to spread south where it has been cooler, leaving behind relatively low temperatures of 20C (68F) to 22C (71.6F) in Northern Ireland and Scotland.
Yorkshire is likely to be the hottest area today, before the South welcomes the top highs tomorrow.
The heat could lead to a few local thunderstorms in the east of the country.
The RAC said more than 11 million motorists were planning to hit the road this weekend.
Popular spots include the Lake District, Devon and Cornwall, the south coast of England, and Yorkshire.
The RAC added that it was boosting the number of its patrol teams following a sharp rise last weekend in hot weather-related breakdowns.