An amber heat health alert has been issued for Brighton and Hove and most of the rest of the country as the hot and sunny weather continues.
Temperatures have reached the high twenties centigrade and could even tip into the thirties, or more than 90F, according to some forecasts.
Met Office meteorologist Amy Bokota said: “In total there are 13 stations that have officially marked it (a heatwave).
“As you go through the next couple of days quite a few extra will be added on to that.
“32C is expected tomorrow, 33C perhaps on Thursday, which is expected to be the peak.
“It will then be 32C right the way until Sunday for some places in the south.”
The UK Health Security Agency upgraded its heat alert to amber as temperatures soared.
The warning covers every region of England apart from the north east, where a yellow alert is in place.
The alerts are in place from noon yesterday (Tuesday 5 September) to 9pm on Sunday (10 September).
Temperatures could start to drop gradually at the weekend, with a chance of thunderstorms breaking out from the north and west of the country, the forecaster added.
Health chiefs have urged people not to spend too long in direct sunlight and to drink enough water to stay hydrated.
The beach lifeguard service ended for the summer on Sunday along the seafront in Brighton and Hove after a fairly damp and dismal spell.
*a few warm days. It’s a heatwave!
In the UK, a heatwave is declared when the daily temperature of a certain location meets or exceeds the heatwave temperate threshold for at least three days. So by definition, yes, it is a heatwave!