Forced to go all in when running out of chips

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What are the general rules of thumb ?

Let's say blinds are $5/$10 with no Ante and you have $50 in chips left.
You will survive 3 more rounds of small and big blind. ($15x3=$45)
That means you have 30 more hands left in a table of 10 players.
(Assuming the blinds are fixed for now)

So, there really is no urgency in pushing all in, right?

It's more clear when you are on your last round and the next set of blinds will bankrupt you, so then it's more clear to just go all in with a J8 or whatever, since odds are, you won't get such a high card in the next few hands.

But, when you have a few rounds left, don't panic, right?

I tend to shove with any 2 cards with combined value of 15+
Is that correct play?