Saw this topic elsewhere. So this is the scenario:

Say someone is the only match for someone who needs a kidney or a bone marrow transplant (or something like that). If the person doesn't get the get transplant, they will die. Should they be legally compelled to donate? 

Or even - let's say it's not a random stranger, and that the law would be limited to immediate relatives. 

Morally, I think most people would feel an obligation to save the life of their relative. But it's a very different thing to make it legally mandated, especially since there are so many other factors - bodily autonomy, obviously, but also stuff like organ donation is a serious procedure with pretty serious possible consequences, to say nothing of the question of whether it would be medically advisable for you to do so. (I mean, it'd be really hard to legally define EVERY possible medical condition that would justify an exception. Especially since so many might be fine or might be deadly, depending on your own personal health.)