Officials sent out health warnings today as the Midlands continued to swelter in the country's first heatwave for seven years.
After five consecutive days basking in 30C-plus temperatures, forecasters said Britain was in the midst of its first prolonged heatwave since 2006.
The Met Office responded by issuing a "level three heat health watch" for London and the South East and advised "alertness and readiness" for those in the North West and North East.
Level three warnings are only one notch below the most serious alerts and are put out when high temperatures place the very young, the very old and those with chronic diseases at risk.
Forecasters said that Wednesday could again break the record for the warmest day of the year, with temperatures expected to creep up as high as 32C (89.7F) in parts of England.
Gemma Plumb, forecaster with MeteoGroup - the weather division of the Press Association - said: "There is no proper definition of 'heatwave' in the UK - but we are undoubtedly in the midst of one now.
"It is the longest period of hot weather since 2006, with prolonged temperatures above the average for the time of year.
"Normally we can expect it to reach 20-22C (68-71.6F) in England and Wales - today parts of the Midlands, East Anglia, the south coast and London could see 30C-plus."
And sun-worshippers can expect to enjoy balmy Britain for a while yet.
Miss Plumb said: "At the moment it looks as though the warm weather is going to stay well into next week at least."