How are emergencies different from other medical situations?

Three criteria are necessary for an event to be an emergency: (a) there must be an expectation of serious harm; (b) there must be an expectation that someone can do something to prevent or reduce that harm; and (c) there must be time pressure. Because emergencies are unique in having this set of criteria, standard moral principles, when applied to emergency situations, can require actions that are prohibited in other situations. This can give the impression that there are different moral principles at work in emergencies. This paper argues that this impression is illusory.