Non-Critical Illness on Shabbos
7. A person who [superficially] wounded his hand or foot, may soak it in wine to cause the bleeding to stop. He may not use vinegar (1) for this purpose, because it is powerful, [and thus it is obvious that] he is employing a remedy. If the person's constitution is delicate (2), wine is equivalent to vinegar and is also forbidden (3).
If the wound is on the back of his hand, on the back of his foot, or was caused by a metal object, any substance may be used to heal it (as will be explained in Chapter 92, Law 5) (4).
(1) Or whisky (Mishna Berura328:92).
(2) That is, he has soft skin.
(3) One must do what is necessary to prevent infection, or to prevent the condition from worsening, such as washing the wound with water, or hydrogen peroxide. We will see the many different criteria which define what type of remedy is permitted and in what circumstances, as we proceed through this chapter. See HY 91:5 for a description of how ill one must be in order to violate the rabbinical prohibition against taking a remedy on Shabbos.
(4) These are examples of cases in which there is a clear danger of infection. As we saw in earlier halachos, if there is any possibility that a wound may result in a life threatening condition, one may violate even Biblical laws, if necessary.