Need the source of a story about a father and son lost in the desert.

[EccentricCircle]

A man and his son are lost in the desert, they have one bottle of water. The son is desperately thirsty and asks for the water but the father says "No, If you drink the water then we'll both die, if I drink the water then I can get you to saftey"

I've no idea what the origin of this is, whether its a parable or an event from a more recent work of fiction, but could do with finding out the source.

So, has anyone heard it before?

[Raimun]

No, but I've heard that, in an aeroplane, you should put the oxygen mask first to yourself before you put it to a child.

[EccentricCircle]

Thats a good point, and certainly the same principle