Here is an example of one of the few U.S. state statutes that impose a legal obligation for a person to help a stranger:

Duty to Aid the Endangered Act, Vermont Statutes, Title 12, Chapter 23 ;SS 519:

Emergency Medical Care

(a) A person who knows another is exposed to grave physical harm shall, to the extent that the same can be rendered without danger or peril to himself or without interference with important duties owed to others, give reasonable assistance to the exposed person unless that assistance or care is being provided by others.

(b) A person who provides reasonable assistance in compliance with subsection (a) of this section shall not be liable in civil damages unless his actions constitute gross negligence or unless he will receive or expects to receive remuneration. Nothing contained in this subsection shall alter existing law with respect to tort liability of a practitioner of the healing arts for acts committed in the ordinary course of his practice.

(c) A person who willfully violates subsection (a) of this section shall be fined not more than $100.00 -- 1967 No. 309 (adjourned session) SS 2-4 effective March 22, 1968.

Here is a rare case where a person asked a court to force another person to donate body parts in a situation of medical necessity.

McFall v. Shimp
No. 78-177711 (July 26, 1978)
10th Pennsylvania District, Allegheny County

Flaherty, [Judge].

The Plaintiff, Robert McFall, suffers from a rare bone marrow disease [aplastic anemia, a disease where the patient’s bone marrow fails to manufacture certain necessary blood components.] and the prognosis for his survival is very dim, unless he receives a bone marrow transplant from a compatible donor. Finding a compatible donor is a very difficult task, and limited to a selection among close relatives. After a search and certain tests, it has been determined that only the Defendant [David Shimp, a first cousin to 39-year-old McFall] is suitable as a donor. The Defendant refuses to submit to the necessary transplant, and the before the Court is a request for a preliminary injunction which seeks to compel the defendant to submit to further tests, and, eventually, the bone marrow transplant.

Although a diligent search has produced no authority, the Plaintiff cites the ancient statute of King Edward I, St. Westminster 2, 13 Ed., I, c 24, point out, as is the case, that this Court is a successor to the English courts of Chancery and derives power from this statute, almost 700 years old. The question posed by the Plaintiff is that, in order to save the life of one of its members by the only means available, may society infringe upon one’s absolute right to his "bodily security"?

The common law has consistently held to a rule which provides that one human being is under no legal compulsion to give aid or to take action to save that human being or to rescue. A great deal has been written regarding this rule which, on the surface, appears to be revolting in a moral sense. Introspection, however, will demonstrate that the rule if founded upon the very essence of our free society. It is noteworthy that counsel for the Plaintiff has cited authority which has developed in other societies in support of the Plaintiff’s request in this instance. Our society, contrary to many others, has as its first principle, the respect for the individual, and that society and government exist to protect the individual from being invaded and hurt by another. Many societies adopt a contrary view which has the individual existing to serve the society as a whole. In preserving such a society as we have it is bound to happen that great moral conflicts will arise and will appear harsh in a given instance. In this case, the chancellor is being asked to force one member of society to undergo a medical procedure which would provide that part of that individual’s body would be removed from him and given to another so that the other could live. Morally, this decision rests with the Defendant, and, in the view of the Court, the refusal of the Defendant is morally indefensible. For our law to compel the defendant to submit to an intrusion of his body would change the very concept and principle upon which our society is founded. To do so would defeat the sanctity of the individual, and would impose a rule which would know no limits, and one could not imagine where the line would be drawn. This request is not to be compared with an action at law for damages, but rather is an action in equity before a Chancellor, which, in the ultimate, if granted, would require the submission to the medical procedure. For a society, which respects the rights of one individual, to sink its teeth into the jugular vein or neck of one of its members and suck from it sustenance for another member, is revolting to our hard-wrought concept of jurisprudence. [Forcible] extraction of living body tissue causes revulsion to the judicial mind. Such would raise the specter of the swastika and the inquisition, reminiscent of the horrors this portends.

The court makes no comment on the law regarding the Plaintiff’s right in an action at law for damages, but has no alternative but to deny the requested equitable relief. An Order will be entered denying the request for a preliminary injunction.