It's been a classic week for soldiers fainting in the presence of royalty. A soldier keeled over yesterday waiting for Prince Charles in Oslo, and on Saturday no fewer than three soldiers fainted at Aldershot. Here's a great video of one going down like a sack of potatoes. Notice the way his colleagues are reluctant to break ranks and help the poor man to his feet.
It happens to soldiers because standing still for a long time with a warm and weighty hat on your head interferes with the circulation of blood.