According to George Shapiro, the show received negative letters from real-life "bubble boys" and their families because of this episode.
The 20th anniversary edition of Trivial Pursuit features a card with the question, "What series co-creator supplied the voice for Seinfeld's Bubble Boy?" According to the card, the answer is Larry David. It's a misprint. It should say Jon Hayman.
The "Moors/Moops" incident shown is based on an actual error spotted by Seinfeld writer Bill Masters while they were playing the home edition of Jeopardy.
The diner that Elaine and Jerry eat at is the same set as Reggies, the bizarro diner that parallels Monk's.
O-Lan Jones, who plays the diner waitress, was often typecast in waitress and barmaid roles, playing similar characters in a number of movies such as Natural Born Killers (1994) and The Truman Show (1998).