UK Metoffice Red/Amber Weather warning, early next week.
Expect it to be more than just "a nice bit of summer weather" and check the NHS heatwave advice https://www.nhs.uk/live-well/seasonal-health/heatwave-how-to-cope-in-hot-weather/
And if you don't have oral rehydration solution in stock know the recipe for home making it https://rehydrate.org/solutions/homemade.htm
Also if you're going to think you want a fan (hand held/desktop) or ice lollies stock up now basically and take care of yourselves this could be a grim couple of days.