Marshall Teague, who played the lost camper, later appeared in the Season 6 episode "The Assassin".
The cast ranging from oldest to youngest in real-life is Kevin McCarthy (b. 1914, 78 at the time of the episode), J. A. Preston (b. 1932, 60 at the time of the episode), Madge Sinclair (b. 1938, 54 at the time of the episode) and Margot Kidder (b. 1948, 44 at the time of the episode).
The title is from the old idiom "Curiosity killed the cat."