The Met Office reported the maximum temperature attained so far on Wednesday was 33.7C in Cavendish in Suffolk.
Nonetheless, it says eastern and southern England may observe a record-breaking 39C (102.2F) on Thursday, beating the all time large of 38.5C by 2003.
A body was discovered following three people went lost in various areas of the River Thames on Tuesday.
The temperatures have been focused in eastern and southern England. Writtle at Essex found 33.5C, although the mercury rose to 32.4C in Heathrow and 31.9C in St James’s Park, London.
Scotland and northern Ireland are the areas with highs in the 20s.
Forecasters say there was a 60 percent likelihood the document for the maximum temperature could be broken on Thursday.
Thunderstorms swept across all the UK on Tuesday using 48,000 lightning strikes.
The NHS has tweeted information for handling the hot temperatures and stated:”Try to prevent spending prolonged periods in the sun this past week. Moreover, be mindful that vulnerable men and women are at higher risk of health problems.”
The London Ambulance service included:”When catching a train or the Tube in this hot weather be sure to carry a jar of water and measure off the train at the next station if you’re feeling unwell.”
Councils have called on people to check on loved ones and friends, warning the elderly and people with respiratory and heart difficulties were most in danger from the hot weather.
Network Rail has stated rate restrictions might have to be released Thursday”at exposed places” to”decrease the odds of buckling”.
It advised passengers until they travel to check their trains.
Rail operator Southeastern has stated it’ll run a”substantially decreased service” on Thursday on account of the speed limitations.
The Rail Delivery Group, which reflects the market, advised passengers in London and the South East to think about altering their travel plans on Thursday due to the anticipated heat.
Meanwhile, the passengers on a Eurostar train traveling from Brussels to London were stranded in 38C on Wednesday morningand following their train resigned because of an overhead electricity supply issue.
Eurostar advised people not to travel on its own Brussels route since the energy issue was causing”significant delays”, in addition to a few cancellations.
Belgium’s record temperature has been busted on Wednesday when 39.9C was first listed as temperatures soared in Western Europe.
The French town of Bordeaux also hit its greatest temperature since records started, registering 41.2C (106.1F).