I am seeking to identify a Star Trek TOS (IIRC) episode.
In my unreliable recollection, two Starfleet protagonists out of Spock, Bones, and Kirk are stranded on a planet and have to stay awake until day-break, otherwise risking going to sleep permanently.
I dimly recall that the landscape was arid, and that some sort of gas was released during the night-time; and that if you fell asleep, then the sleep was permanent. The two protagonists kept each other awake by recounting stories to each other.
Any assistance is most gratefully appreciated. Thank you very much.