A Met Office amber warning for extreme heat will start on Thursday and run until Sunday, affecting around half of the Isle of Wight.
National forecasters said: "Temperatures will increase across much of the UK over the coming week.
"Temperatures will be highest across parts of England and Wales with these peaking on Friday and Saturday.
"In addition to high daytime maxima, temperatures overnight will remain very warm, especially in larger urban areas."
As the Isle of Wight County Press reported earlier, a Heat-Health Alert is also expected to be triggered by the sustained high temperatures.
In its latest weather warning, the Met Office says there may be adverse health effects for some, including sunburn or heat exhaustion (dehydration, nausea, fatigue) and other heat related illnesses.
There may also be an impact on travel.
The north and west of the Island is covered by the amber weather warning, while other parts have escaped, but are likely to be very warm.