A third heatwave of the summer is expected in parts of the UK - as officials warn it is likely to have "significant impacts" on health and social care services.
A yellow heat health alert has been issued for sustained high temperatures across the southern half of England from Wednesday at 10am until Tuesday at 10am.
London, the East Midlands, West Midlands, East of England, South East and South West are covered by the UK Health Security Agency (UKHSA) alert.
"Significant impacts" are likely across health and social care services as the Met Office has predicted heatwave conditions in some areas, with temperatures in the lows 30s centigrade by the end of the week, the alert states.
Paul Coleman, a Consultant in Public Health at UKHSA, urged people to take "sensible precautions" in the sun, warning even moderate heat "can result in serious health outcomes, especially for older adults.
A hosepipe ban has been issued by Yorkshire Water, which comes into force on Friday.
Two amber heat health alerts were issued in consecutive weeks during two separate heatwaves in June, which provisional Met Office figures suggest will England's warmest on record.
An official heatwave is recorded when areas reach a certain temperature for three consecutive days, with thresholds varying from 25C to 28C (77-82F) in different parts of the UK.
Sky weather producer Jo Robinson said high pressure over the UK will see temperatures climb each day across most areas.
Much of central and southern England, Wales and parts of Scotland will see heatwave conditions, making it more widespread than the last one, she said.
Temperatures are set climb to 30C (86F) and above for five days from Thursday in some areas, with top temperatures of around 32C (90F) on Friday and over the weekend - and a small chance of 34C (93F), Ms Robinson added.
"It's homegrown heat rather than drawing something in from the near continent so we're unlikely to reach the UK's highest temperature of the year so far", which stands at 35.8C (96F) at Faversham [in Kent] on 1 July, she said.
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Ms Robinson said it will be "humid but perhaps not quite as muggy as the end of June" and people can expect "uncomfortably warm nights by the weekend".
She warned the heat health alert "may well be upgraded over the next few days".
The Acropolis in Athens was closed for several hours on Tuesday afternoon and mandatory work breaks were introduced in several other regions, mostly on islands and parts of central Greece, where temperatures topped 40C (104F).
The risk of wildfires, already "very high" across the eastern mainland, is expected to increase during the week, Greek authorities said.
(c) Sky News 2025: Week-long heat health alert issued for parts of England as temperatures set to soar
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