Okay, so as someone who has fainted multiple times, the best port of call is to contact emergency services AND to put the patient's legs up on a chair or a table. Usually, fainting is caused from a lack of blood supply in the head, which is why you collapse. Elevating the legs allows for blood to flow back up to the brain. But! You don't want to move the patient too much. Avoid touching the neck/head area especially because that can cause problems.