Not dying....
The FITV is a plunger with a wax mechanism. When the coolant from the engine running through it is cold, the plunger is keeping a bypass open to allow more air past the throttle plate, thus raising the idle to decrease the warm up time durring idle and get the much needed oil temperature up. Once the coolant gets up to temperature, the wax expands and the plunger closes, reducing the bypass air to only the air getting past the throttle adjustment screw and the IACV (if equiped).
You can run an aftermarket throttle body lacking the FITV with no issue. In the same respect, you can also run a throttle body with a detachable FITV by putting a blockoff plate over the hole to prevent the extra air from always getting in. It has no electronics, and cannot throw a code.