When Howard's mother reacts negatively to the news that he's engaged to Bernadette, she ends up in the hospital, where Sheldon has to combat his fear of germs.
- No Sympathy: Due to being worried about Howard's mother, everyone ignores Sheldon's pleas to drive him back to the apartment.
- Shaped Like Itself:
Howard: It was either a heart attack or a heart attack-like event.
Penny: What's the difference?
Sheldon: A heart attack-like event is an event that's like a heart attack.
- Terrified of Germs: The focus of Sheldon's plotline. First he freaks out over accidentally drinking from Leonard's glass at the Cheesecake Factory, then again when Raj makes Sheldon believe he drank from his glass. Later the gang go to the hospital to visit Howard's mother, which naturally makes Sheldon apprehensive, but that's nothing compared to what happens at the end, when he accidentally wanders into a quarantined room and has to be locked inside.
Penny: Oh, don't tell me you're afraid of germs.
Sheldon: Not all germs. Just the ones that will kill me. The same way I'm not afraid of all steak knives, just the ones that might be plunged in my thorax.