Heatwave: Household Cavalry battles 'pressure cooker' conditions
While London faces sweltering temperatures, the duties for the Household Cavalry Mounted Regiment must go on as usual.
Since 1660, the soldiers of the Household Cavalry, a ceremonial regiment based in the capital's Knightsbridge, have acted as the monarch's protectors.
Forces News has been to Horse Guards Parade to see how the troopers are coping in the heatwave – with temperatures expected to soar to around 40°C and England and Wales facing an extreme heat warning.

As a ceremonial regiment, the Household Cavalry Mounted Regiment represent the monarch and nation, dressed immaculately for the part.
And, aside from state ceremonial occasions, their daily role is providing The Queen's Life Guard at Horse Guards.
Their dashing uniforms are made of wool, with the full kit weighing a whopping 30 kilos. With temperatures reaching 30°C, many experience feeling faint.
According to Trooper Brandon Richards, the key to staying safe in the extreme heat is to take your kit off as soon as you are off duty.
"Personally, obviously, it's quite exhausting, especially when you come in off your stags," said Trooper Brandon Richard, Household Cavalry.
"As soon as you take off the uniform it is a great feeling."
He also drinks as much water as he can, eats fruit and makes sure to stay in the shade as much as possible.
The weather, he says, is "pretty extreme" and everyone is "feeling it, definitely".
To make sure the horses and their riders stay safe in the heat, they are checked up on every 15 minutes to half an hour.
While PT training can be postponed if the heat gets too unbearable, guarding duties must continue no matter what the weather.
The Changing of The Queen's Life Guard happens every day at 11:00, approaching the hottest time of the day.
Taking place on Horse Guards, the daily event has been the responsibility of the regiment since the restoration of the monarchy by Charles II in 1660.
The public gets to marvel at the ceremonious exchanging of duty between The Life Guards and the Blues and Royals.
While on guard, the troopers are not allowed to move which, according to Trooper Jaime Bartlett, is more difficult in the extreme heat.
"You sweat quite a lot, especially with the helmet," he says. "The sweat drips down your eyes.
"Obviously, you have to wear the kit shirt under here, wear your tunic and your cuirass so it gets quite hot. It's like a pressure cooker."
Trooper Bartlett makes sure to stay well hydrated and eats a banana before going out on guard duties.
"The pressure on your head from the helmet is the real problem, no matter the weather, but the heat just adds to it."
The trooper has come close to fainting a couple of times but says he has methods to help him pass the time and mentally deal with the heat while keeping still.
"Where we stand out on guard, there are cobbles. I just count the cobbles or sing a song in my head."