Say it’s very dark o’clock at an airport with no medical services available except for emergency purposes. Will you, literally, call 911 (or the equivalent thereof) to be taken to an ER, where you can get a doctor to sign a piece of paper confirming you said you feel too tired to work? Is that even a thing? I mean, can you even get a doctor to produce such a piece of paper?
I would imagine most cases of fatigue to happen outside the opening hours of a GP doctor.