The first thing our Torts professor said to us was "don't help anyone in danger, you will just get sued".
Some jurisdictions have "good samaratin" laws to protect people from lawsuits.
http://en.wikipedia.org/wiki/Good_Samaritan_Law
In Canada, a good Samaritan doctrine is a legal principle that prevents a rescuer who has voluntarily helped a victim in distress from being successfully sued for 'wrongdoing'. Its purpose is to keep people from being reluctant to help a stranger in need for fear of legal repercussions if they were to make some mistake in treatment.[1]
In Canada, good Samaritan acts are a provincial power. Each province has its own act, such as Ontario[17] and British Columbia's[18] respective good Samaritan acts; Alberta's Emergency Medical Aid Act; [19] and Nova Scotia's Volunteer Services Act[20] Only in Quebec, a civil law jurisdiction, does a person have a general duty to respond if he is first-aid or medically certified.[21] In British Columbia, persons have a duty to respond only where a child is endangered.
An example of a typical Canadian law is provided here, from Ontario's Good Samaritan Act, 2001, section 2:Protection from liability 2. (1) Despite the rules of common law, a person described in subsection (2) who voluntarily and without reasonable expectation of compensation or reward provides the services described in that subsection is not liable for damages that result from the person's negligence in acting or failing to act while providing the services, unless it is established that the damages were caused by the gross negligence of the person. 2001, c. 2, s. 2 (1).[22]