QPassage wrote on Aug 23^rd, 2006 at 3:02am:

Actually it holds up very well even in the heat.  Velveeta cheese is a non-perishable product,  until it is opened.

I dispute the "until it is opened" part of qp's statement.

Back in college a roommate of mine left an opened brick of Velveeta on the kitchen table for three weeks...in the middle of summer...in our apartment, a veritable cesspool of moldy junk.  It sat there unblemished by rot of any kind.  When the roommate returned (from a stay at a psych hospital) he went into the kitchen to score a snack.  He saw the V and went for it, spreading the soft goo onto a piece of bread.  A shock of recognition hits his face and he quickly tosses it all into the garbage.

"What's wrong?" I asked him, "that looked perfectly fine."

"That's the problem.  I was gone for three weeks and this didn't rot.  I won't eat anything that doesn't rot,"he said.

I can think of a couple exceptions to his "rule" but that was pretty wise for a schizophrenic.