The French expression: Tomber dans les pommes (pronounced to(n) bay da(n) lay puhm) means to faint or pass out. It has an informal register and literally translates to "to fall in the apples." You might also hear the variation partir dans les pommes (to leave into the apples)
The French expression tomber dans les pommes is a cute way of saying that someone fainted, but I wish I knew why/how apples are related to a state of unconsciousness.* This strange link continues in the equally informal expression rester dans les pommes - "to (continue to) be out cold, to remain unconscious."
*According to Le Grand Robert, the probable origin is George Sand's être dans les pommes cuites, a play on être cuit (to be exhausted) in Rey et Chantreau, but that still doesn't explain what apples have to do with anything.
N'ayant rien mangé depuis plus de 12 heures, elle est tombée dans les pommes.
Not having eaten anything for more than 12 hours, she passed out.