Probably. For instance, I would try to defend my wife/child from imminent physical harm even if it put me in a lot of danger.

How many people you didn't know would you equate to being "of equal concern" to you as one person you do know when deciding whether or not it's worth it to risk your own life to save them? Please express this as a ratio -- unknowns:knowns -- and then, if you like, knowns:loveds.