Tiffani Adams said she fell asleep while flying from Quebec to Toronto on 9 June. When she woke up, she was freezing cold and still buckled into her seat, but the aircraft was parked.
She said she had experienced "reoccurring night terrors" since the incident took place.
Air Canada has confirmed the incident occurred and is investigating.
Ms Adams said on Facebook that she woke up "around midnight [a few hours after the flight landed] freezing cold still trapped in my seat in complete darkness."
She said the experience was "terrifying".