This is a discussion on Risking your whole stack? within the online poker forums, in the Tournament Poker section; Why in some times we are good in a tournament, but in some sines we put our all chips in risck?!
If we have 35BB is
I don't think it's just a matter of whether you have more or less bb than your opponent, I think there are many variables that influence the decision to bet everything against a player who has more or less bb than you, for example if that player against whom Do you want to bet everything? Is it a player who has been playing aggressive? Are you close to the bubble? Is that all-in just a bluff attempt or are your cards really good for betting everything?
There are a few situations where a push puts on enough pressure on opponent to get the fold. Otherwise bet for value. I like Phil Helmuth philosophy of trying to play tourney without having to get it all in and risking tournament life.
I think if you don't really care about outcome you can do it to double up quickly. Or push pocket aces early when some players might call with a very wide range.
And in general 13 BBs or less is the reasonable stack size for push.