The Met Office has issued an amber extreme heat warning as temperatures look set to hit the high 30s this weekend.
The amber grading, which has been issued for Sunday, warns of adverse health effects for the general public, not just those most vulnerable to extreme heat.
Temperatures could be in excess of 35C in the south-east (95F), and around 32C (89F) elsewhere within the warning area.
These high temperatures are expected to extend into the early part of next week and meteorologists will consider whether to issue an extension to the warning in the coming days.
The area covers nearly all of England as far north as Sunderland and the eastern half of Wales.
What is an amber weather warning?
The Met Office issues weather warnings when severe weather has the potential to affect health, power supplies, travel and water availability. The warnings are given a colour - yellow, amber or red - depending on a combination of both the impact the weather may have and the likelihood of the impacts occurring.
An amber warning is issued when there is an increased likelihood of severe weather affecting day-to-day lives. This means there is the possibility of travel delays, road and rail closures, power cuts and the potential risk to life.
This could be through floods, storms, or extreme heat.
The Met Office advises that people think about changing plans and taking action to protect themselves if an amber warning is in place. It issued the amber alert on Monday as part of an Extreme Heat Warning based on consecutive days exceeding average temperatures across the country.
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Met Office deputy chief meteorologist Rebekah Sherwin said: “Temperatures are likely to peak at 33C in the southeast on Monday and Tuesday, with warm weather likely to continue throughout this week.
"It looks likely to ramp up late this week and into early next week.
“From Sunday and into Monday, temperatures are likely to be in excess of 35C in the southeast, although the details still remain uncertain. Elsewhere, temperatures could be fairly widely above 32C in England and Wales, and in the mid-to-high 20s Celsius further north.”
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How dangerous is it?
An amber weather warning indicates a risk to life if not prepared for and dealt with appropriately.
Dr Agostinho Sousa, head of Extreme Events and Health Protection at the UK Health Security Agency (UKHSA), said: “Heat-health alerts have now been issued to the majority of the country, with temperatures set to remain consistently high throughout the duration of this week.
“Most of us can enjoy the hot weather when it arrives, but it is important to keep yourself hydrated and to find shade where possible when UV rays are strongest, between 11am and 3pm.
“If you have vulnerable family, friends and neighbours, make sure they are aware of how they can keep themselves protected from the warm weather.’’