Yellow heat health alerts came into effect across central and southern England on Friday morning with temperatures forecast to reach 30C (86F) in places.
The alerts, issued by the UK Health Security Agency (UKHSA), cover the East and West Midlands, eastern England, London, south-east England and south-west England and are valid from 09:00 BST on Friday until 09:00 on Sunday.
The UKHSA warns that heat is expected to cause minor impacts for health and social care services, with an increased risk to life for vulnerable people.
It comes as parts of the UK prepare to see much-needed rain this weekend – although amounts are expected to be relatively small, especially in the south.
A drought was officially declared for large parts of north and mid-Wales on Thursday.
The rest of Wales, along with much of central, southern and eastern England, is in “prolonged dry weather” category – one stage below a drought.
Hosepipe bans are in force for millions of customers.
