When dealing with saving lives on Shabbat, a serious dilemma arises. On the one hand, it would seem to be preferable to use a shinui when doing whatever melakhot are necessary. After all, when a melakha is done in the normal way, one violates Torah law, while when it is done with a shinui, one transgresses only rabbinically (above 9:3). On the other hand, when it comes to saving a life on Shabbat, the Sages proclaimed that “One who acts quickly is to be praised” (Yoma 84b; SA 328:2). If so, it would seem preferable to refrain from placing constraints upon one who is attempting to save a life. Rather, he should act as he would on a weekday, as efforts such as minimizing Shabbat desecration or attempting to do the melakhot with a shinui are likely to slow him down. This is especially true if he thinks it is necessary to consult with a rabbi about how to act when a person’s life is in danger.
In practice, the basic principle is that rescue efforts must be undertaken in the best and fastest way possible. If trying to do melakhot with a shinui is likely to delay treatment, it is preferable to do them in the normal fashion, without any shinui. This is because according to halakha, the rescuer may do melakhot in the normal way, since saving a life overrides Shabbat. Nevertheless, when it is clear that a shinui will not hamper the rescue in any way, it is preferable le-khatĥila to make use of a shinui. Therefore, it is advisable for doctors, nurses, and emergency medical workers to learn how to minimize Shabbat desecration while saving a person’s life.
There is a similar dilemma regarding treatments normally administered to a gravely ill patient during the week, some of which are not necessary to prevent his death. Since the caregivers do not know which treatments are truly necessary and which are not, they must treat the patient just as they would treat him during the week. However, one who understands medicine and knows for certain that a specific melakha is not necessary to save the patient, or that the treatment can be postponed until after Shabbat, he should avoid doing the melakha on Shabbat (SA 328:4). Palliative treatments are administered on Shabbat even when it is clear that they do not treat the disease, because when the patient’s pain is reduced, he will have more strength to overcome his illness.