The Met Office has released an amber weather warning for Sunday 17 July, where temperatures could reach up to 32C.
The UK is already in a heatwave, with most of the country enjoying temperatures close to 30C, but this “rare extreme heat” warning suggests the climate is about to take a bit of a dramatic turn.
The weather website explains: “Some exceptionally high temperatures are possible during Sunday and could lead to widespread impacts on people and infrastructure.”
An amber warning also means that “population-wide adverse health effects are likely to be experienced, not limited to those most vulnerable to extreme heat”.
It adds that this could lead to “potential serious illness of danger to life”.
Substantial changes in working practices and daily routines are expected, while a wave of people visited coastal areas could lead to a rise in water safety incidents.
Delays on roads and road closers are potential too, while railways and airlines could be affected as well.
There are no other warnings in place for the rest of this week, although the Met Office believes temperatures will build in the coming days and peak on Sunday and Monday.
Warm nights and hot days are expected too, with the hot weather continuing into the beginning of next week.
The Met Office added: “An update extending this warning into Monday is likely.”