Yellow heat health alerts are in place across parts of the UK despite forecasts of rain this weekend.
The warnings came into place at 9am on Friday and will remain until 9am on Sunday, and cover the East Midlands, West Midlands, South East, South West, the east of England and London.
The UK Health Security Agency (UKHSA) said the hot weather could have an impact across health and social care services and put vulnerable people at risk.
Health chiefs also warned water‑related incidents may increase, including risks from cold water shock and drowning.
Temperatures are set to hit 29C on Saturday in London and 28C in Birmingham and Norwich, but rain is also forecast.
It comes after three consecutive heatwaves and one of the driest springs on record with hosepipe bans in place across the country.
Showers are expected to roll in across Scotland, Wales, and Northern Ireland on Saturday evening, before spreading further across the UK on Sunday.
Met Office chief forecaster Steve Willington said: “The high pressure has been a key feature of the UK’s weather forecast over the last few weeks, bringing above-average temperatures and extremely dry conditions for many.
“However, we will begin to see a modest change as a weak weather front pushes south across the UK on Saturday bringing some much-needed rain, albeit light and mainly concentrated in the North and West. Behind the front, a showery air mass will bring potentially heavy showers, some of which may be thundery.”
Greg Wolverson, Met Office deputy chief forecaster, explained cooler weather can be expected from Sunday onwards, but temperatures will still remain average for the time of year.
“Although there is a return to rain in the forecast, we have just come out of an exceptionally dry spell and the forecast rain is unlikely to be widespread or substantial,” he said. “Many areas are likely to continue experiencing prevailing dry conditions for the foreseeable future, especially in southern England.”
The heat alert comes as millions of motorists are expected to take to the roads for summer getaways this weekend. The AA said around 6.3 million drivers are planning a road trip of more than 100 miles between Friday and Thursday.
The Port of Dover is expecting another busy weekend but has worked to smooth any delays caused by new EU border checks.
Met Office weather forecast
Saturday
Band of rain across Scotland moving southeastwards and turning increasingly showery. Remaining dry, sunny and very warm across southern areas, with brighter and fresher conditions following across Scotland.
Sunday to Tuesday
Fresher for all on Sunday with sunny spells and some showers. Remaining changeable early next week across the North, but potentially turning dry and very warm again in the South.
