"I was very scared. But I was more concerned about how it may have affected other people involved," said the 22-year-old, who is serving national service.
Even though it turned out to be a false alarm, the experience had such an impact on him that it became his source of inspiration for a 15-minute film he wrote and directed.
Titled November, it has been nominated for three awards at the inaugural National Youth Film Awards (NYFA) - Best Direction, Best Screenplay and Best Editing.
NYFA is a film-making competition organised by *Scape and local film project consultancy management and training company Sinema Media.
Out of the 238 submissions received this year, 47 were nominated across 14 categories. The winners will be announced in an awards ceremony at *Scape on Aug 2.
On why he wanted to delve into this personal aspect of his life, Mr Lim said: "I wanted to make a film that was personal and sincere, yet something that people can connect with.
"We have all experienced young love and the ignorance of youth and this film is about the point in our lives where we transition to adulthood."
He declined to elaborate on his relationship status at the time of the scare or give further details about the episode.
November is a fictional film about a teenage couple whose relationship goes through a tumultuous period when Kai (played by Koh Kah Yong) tests positive for herpes and his girlfriend Min (Cara Chiang) is forced to deal with his infidelity and face her own fears.
Mr Lim, a former Ngee Ann Polytechnic student with a diploma in film, sound and video, said: "I was worried the audience may think of it as a sexually transmitted disease awareness film.
"But I did not want to focus on sex or the disease. I wanted this film to touch on human relationships and the emotional aspect of the story."
To make the characters as authentic as possible, Mr Lim introduced elements of improvisation for the actors, who were not given scripts beforehand and would know about the scene only before each take.
The team would then discuss the lines before the cameras started rolling. Each scene required around four takes and the film was shot over three weekends last year.
Mr Lim and co-writer Angelica Ho won Best Script for November at this year's Singapore Short Film Awards. The film was also nominated for Best Short Film at the 31st Los Angeles Asian Pacific Film Festival in April.
Mr Lim said of the film: "I think (the experience) has made me realise that our lives are connected and my actions not only have consequences towards myself, but to those around me as well."
Members of the public can watch the nominated films from July 24. Screenings are free.
For more details, go to http://scapers.sg/events/nyfa.screen
This article was first published on July 3, 2015.
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