LEV509 The obligation to save a person from any hazard to his life or health devolves on anyone able to do so. Every person is duty-bound not only to protect his own life and health, (Yoreh De'ah, 116; Hoshen Mishpat, 427:9-10) but also those of his neighbor (Hoshen Mishpat, 426:1, 427:1-10). Anyone refusing to come to the rescue of a person in danger of losing life, limb or property is guilty of transgressing the biblical law "Thou shall not stand upon the blood of thy neighbor" [this verse, Rashi a.l.] It is questionable, however how far one must, or may, be prepared to risk one's own life or health in an effort to save one's fellow; the duty, and possibly the right, to do so may be limited to risking a less likely loss for a more likely gain. (Bet Yosef, Hoshen Mishpat, 426; for details, see Jakobovits, Jewish Medical Ethics, p. 96f). In any event, when there is no risk involved, the obligation to save one's neighbor from any danger is unconditional. Hence the refusal of a doctor to extend medical aid when required is deemed tantamount to bloodshed, unless a more competent doctor is readily available (Yoreh De'ah, 336:1).