Scenario: A loose player goes all in when you have AA (or KK) with a large stack ($40-$60) Do you call?

I had cowboys last night, guy went all in, luckily I had only just arrived and had about $14. He shows 45s and hits a straight (or flush, I can't rem).

But do you consider it worth that risk pre-flop with a larger stack (say $50 like I managed to win the other night ) just because you have the best pre-flop hand?