This Saturday has been marked the hottest day of the year as the UK bakes in 30°C heat.
While many sunbathers have flocked to beaches this Saturday, at least three overwhelmed soldiers have fainted during the final Trooping the Colour rehearsal.
The sweltering heat has been described as 'sauna'-like conditions by the youngest soldier who was at the Horse Guards Parade in St James's Park.
Prince William has since thanked his soldiers for participating in the face of such 'difficult conditions'.
He tweeted: 'A big thank you to every solider who took part in the Colonel’s Review this morning in the heat Difficult conditions but you all did a really good job. Thank you. W.'
The extreme heat in some areas today may be hotter than Marbella, Ibiza and Tenerife, as amber heat alerts have also been raised.
Thousands gathered at St James’s Park to witness The Colonel’s Review ahead of Trooping the Colour during the King’s Birthday Parade next week.
Today's ceremony involved hundreds of horses and soldiers carrying out complex battlefield drill manoeuvres to military music.
But amidst the scorching temperatures, three soldiers fainted and were carried away on stretchers while two more were helped off the parade ground.
James Calford, 18, from Cardiff, who was the youngest soldier in the Welsh Guards to take part, described the rehearsal as 'like being stood in a sauna with a 200kg dumbbell in your left hand'.
'Once you have got your tunic and bearskin on and carrying your rifle in heat it is incredibly uncomfortable,' he said, adding: 'is a lot harder than it looks on the TV.'
Despite these harsh conditions, storms are on the way tonight, with further warnings issued in large parts of the UK with the potential to cause travel chaos and power cuts later on.
Hail could even be on the cards, according to the Met Office, which explained that rising warm air from the south could bring a mix of conditions.
Chief meteorologist Frank Saunders said: 'As the heat builds from the south, thundery showers will develop through Saturday afternoon.
'While not everyone in the warning area will see the heaviest showers, or even any rain at all, some will bring heavy thundery downpours.
'With intense showers there is a risk of surface water flooding which could cause some disruption.'
Wales and parts of southern and central England are most vulnerable to disruption today, with yellow storm warnings issued from 2pm to 9pm.
A second storm warning is also in place from midday to 9pm in Wales, Northern Ireland and most of western and central England and Scotland.
But eastern and northern Scotland are likely to miss the worst of the extreme conditions.
The risk of thunderstorms will then grow more widely on Sunday in western and central areas of the UK, while southern parts continue to see 30°C heat.
Forecaster Tomasz Schafernaker said these temperatures will last well into the evenings, but are far from rare at this time of year.
