I've never wondered until now!
But I have wondered about what would happen if I died or went into a sudden coma or something, and what my children would do about it, and if they would be found before they hurt themselves.
I have told DS that if ever he can't wake Mummy up, he has to call 999. (This will obviously backfire one day, when on a saturday I tell him to bugger off and play with his train, because I want to carry on sleeping! )