The Met Office has warned health professionals to be 'alert and ready' as the highest temperatures of the year are forecast.
A 'level 2' warning has been issued between midday today and 6pm on Thursday as daytime and nighttime temperatures look likely to be five degrees above average.
Daytime temperatures today will peak in London at 30C (86F) and look likely to get as high as 33C (91F) tomorrow.
That will mean parts of the UK are hotter than LA (31C), Ibiza (28C) and Thailand (29C). From a healthcare perspective it is the high overnight minimum temperatures which pose the biggest threat as some people are unable to cool down or sleep.
Tonight and tomorrow night we could break the record for warmest overnight minimum temperature which currently stands at 22.3C (the average daytime high for this time of year).
To count as an official heatwave the high temperatures have to last for five consecutive days and nights. This mini heatwave won't last that long but Public Health England warns that it will still pose a risk to the 'very young, very old or those with chronic disease'.
Unsurprisingly the unbroken sunshine and high temperatures mean there is an added risk of sunburn and sunstroke. Today's UV Levels of 8/10 are as high as we get in the UK.