As many as 259 people queueing to see the Queen Elizabeth II lying-in- state needed medical attention on Saturday, as night time temperatures dropped as low as 4C.
The figure was released by St John's Ambulance Service, which, along with the London Ambulance Service, has been providing medical help to those lining up or visiting the area to pay their respects.
The charity said that overall, 403 people in the "ceremonial areas" of London required medical support on Saturday and 19 of these were taken to hospital.