What is an "environmental" test ?

In computer systems I have seen levels of testing. Cat 0 might be factory test Cat 1 might be test at customer site Cat 2 is environmental test Shouldn't environmental test provide a dynamic, including a realistic, environment the software runs in. Because we might find out later that the Cat 1 test was a static test. (for example in a missile system, it might all work when the sea is flat. But in high sea missiles might be launched from the wrong side of the ship etc., because the software is unable to handle the varying angles) I bet most contactors cut corners and say something like - we tested the computer at 100% humidity therefore we've done the environmental test.