A royal guard collapsed while watching over the coffin of Queen Elizabeth II in Westminster Hall overnight.
The guard, who appeared to be a member of the Royal Company of Archers, the sovereign’s bodyguard in Scotland, was standing at the foot off the late monarch's casket when he suddenly fell to the floor.
Footage shared on social media shows police rushing to help as gasps can be heard from mourners queuing to see the queen’s casket.
The Archers guarded the queen’s coffin round the clock while the cortege made its way from Balmoral to Edinburgh earlier in the week. Members are now keeping vigil at Westminster alongside the Gentlemen at Arms, the Yeomen of the Guard, at Westminster Hall.
There are 530 members of the Archers, who must be Scottish or have strong connections to the country. They wear green uniforms with a beret finished off with a feather and carry bows. The company still functions as an archery club, the purpose for which it was originally formed in 1676.
Guards are prone to fainting because they must stand still for long periods of time, leading blood to pool in their legs, making it harder for it to return to the heart. Heat, dehydration and tiredness are also risk factors.
The problem is so common, guards are actually taught to faint in a particular way, toppling forward face first, while still holding their rifles, or bow, in the guard's case on Wednesday night in Westminster.
The queen's casket will lie in state until the morning of Monday's state funeral. Tens of thousands of people are expected to file past to pay their respects before then.