Is it? If so how could I check without taking it somewhere?

 

Is it possible? Yes it is. It's not a myth. Especially if it's been severely overheated. You can use a straight -edge and a feeler gauge to check if the deck is level.

You really should try honing those search skills.

 

Yes, a block can warp. If it is warped, do yourself a favor and buy a new one.