A polar expedition discovers a human body in the ice. It turns out that it is possible to bring him back to life. He is identified as Paul Fournier, the grandfather of Edmée de Tartas (Gensac) who disappeared 65 years ago. The doctors who treat him think that they cannot tell him the truth, because this would be a great shock for him, so they tell him that he has woken up in 1905.
Hibernatus provides examples of:
- Abusive Parents: Of the verbal kind. Hubert Barrère de Tartas doesn't like when Didier doesn't want to date Évelyne because they have opposites personalities.
- Arranged Marriage: Hubert to tries to marry his son Didier with Évelyne Crépin-Jaujard (the daughter of one of his fellow businessmen) so he can merge their companies and have his own fortune. Didier is not interested; he is in love with the maid. The viewer might still sympathize with Hubert, since his wife Edmée really seems to control all off his money.Hubert de Tartas: And your idiot of a son who doesn't go anywhere with Évelyne for one year! It's almost like he doesn't realize that with Crépin-Jaujard's capitals, I will be finally safe from your whims!
- Aw, Look! They Really Do Love Each Other: For all his antagonism with his wife, there is a sweet scene that shows that, deep down, Hubert sincerely loves her:Hubert: Edmée...
Edmée: Did Paul see nothing?
Edmée: If he had discovered you in my bedroom, he would have killed you...
Hubert: He believed I was telling you "good evening".
Edmée: Thank you for the thought, my dear...
Hubert: Charming complicity that reminds us the time of our engagement... The youth of your grandfather has brought a little bit of ours...
- Bedroom Adultery Scene: Hubert Barrère de Tartas pretends to be Edmée's fiancé, so he cannot sleep with her. Still, he does it. The next morning, Paul Fournier enters Edmée's bedroom and Hubert has to hide under the bed.
- Butt-Monkey: Hubert Barrère de Tartas. First, his wife forces him to free Paul Fournier. Then, he is forced to receive Paul in his house, which is transformed to look like a 1905 house. When Paul wakes up, Hubert pretends to be his father and Paul throws him out of the house. Then he has to pretend to be Edmée's fiancé, which means he can only secretly sleep with his wife.
- Chase Scene: When Pr. Bibolini, Hubert and Edmée Barrère de Tartas escape in an ambulance with Paul Fournier, they are chased by the police and Pr. Loriebat.
- Closet Shuffle: Hubert has to hide under the bed when Paul Fournier enters Edmée's bedroom.
- Faux Horrific: Edmée and Hubert Barrère de Tartas are terrified when they see Paul Fournier with a large beard in the hospital.
- Fish out of Temporal Water: Paul Fournier was frozen in 1905. He is woken up in 1970.
- French Maid: Sophie, the maid, flirts with Didier. She is also cheeky with Hubert Barrère de Tartas.
- Happily Ever After: The film ends with the marriage of Paul Fournier and Évelyne Crépin-Jaujard.
- Harmless Freezing: Paul Fournier was accidentally frozen in 1905. After he is thawed out, he is alive and well (there's a technobabble explanation to his miraculous survival).
- Here We Go Again!: The story starts with the discovery of a frozen human body. The story ends with Hubert Barrère de Tartas deciding to be frozen.
- Human Popsicle: Paul Fournier was frozen in 1905. He is woken up in 1970.
- Identical Grandson: Edmée de Tartas looks the same as her great-grandmother, because Paul Fournier mistakes the former for the latter.
- Impoverished Patrician: Hubert is coming from the noble family De Tartas, but is basically penniless without his wife's paychecks: as it turns out, he is just the manager of the packaging company and relies on his wife's fortune and volatile moods. He is in fact counting on his son's Arranged Marriage so he could have a bit of financial freedom: so this is basically Financial Abuse on his wife's part...
- I Need a Freaking Drink: Hubert Barrère de Tartas asks twice for a large Grenache and a large Madeira in a large glass.
- Laser-Guided Amnesia: Paul Fournier has forgotten exactly what is needed for the plot: he has forgotten that he was married, that he had a son and that he went to the North Pole.
- Lysistrata Gambit: Edmée refuses to sleep with her husband Hubert as long as his grandfather has to stay in the hospital.
- Media Scrum: When Pr. Loriebat is in a horse-drawn carriage, many journalists ask him questions.
- Mighty Whitey and Mellow Yellow: The lawyer has two Asian mistresses who are very submissive: they undress him and offer him drinks and food when he is on the phone.
- Minion Maracas: At the height of his epic breakdown where he reveals everything to Paul Fournier, Hubert de Tartas grabs the formerly hibernated man and shakes him vigorously.
- Nobility Marries Money: Hubert Barrère de Tartas, a poor nobleman, is married to Edmée Fournier, a rich commoner who owns a factory. Even if Hubert manages the factory, his wife owns it and she signs all the important documents.
- One Dialogue, Two Conversations: Hubert Barrère de Tartas would like to know when he will receive the Legion of Honor, so he asks one of his guests. The guest thinks he is talking about his own Legion of Honor, so he answers that it is done, because he has received it last week.
- Paper-Thin Disguise: Twice.
- First Hubert puts on a black beard, mustache and tailcoat in order to impersonate the "hibernated"'s father. But while the disguise works, this approach fails spectacularly since the real father was cheating on his wife with an actress and abandoned his family.
- Secondly, he wears another fake mustache and a yellow suit to present himself as Edmée's fiancé. Paul Fournier doesn't seems to put two and two.
- Practical Voice-Over: The prologue, which is used to give information about the discovery of the frozen man, is revealed to be a television broadcast watched by Hubert Barrère de Tartas and his family.
- Road Block: The police sets up road blocks to catch Pr. Bibolini, Hubert and Edmée Barrère de Tartas when they kidnap Paul Fournier.
- Seeking Sanctuary: When they are chased by the police, Pr. Bibolini, Hubert and Edmée Barrère de Tartas seek refuge in an abbey. The police does not dare to enter, so Pr. Loriebat enters alone.
- Sexual Euphemism: Hubert's lawyer tells on the phone that he has to study two cases, while he is in his bed with two Asian women.
- Slipping a Mickey: On the plane, Pr. Bibolini tampers his colleague's drink with a drug, so that Pr. Loriebat falls immediately asleep.
- Swing Low, Sweet Harriet: When he pretends to court Edmée, Hubert Barrère de Tartas puts her on a swing.
- Tomato in the Mirror: Paul Fournier thinks that he has woken up in 1905, that Edmée is his mother, that Didier is a student... In short, he thinks that he has resumed his normal life. In the end, Hubert reveals to him that he has woken up in 1970 and that everyone lied to him to make him believe that he is still in 1905. He does not believe Hubert at first, but then he finds a TV set.
- Ugly Guy, Hot Wife: Hubert (De Funès) and Edmée Barrère de Tartas (Gensac).
- Villainous Breakdown: Probably De Funès's most epic breakdown to see; after realizing that the "hibernated" love affair with his friend's daughter will ruins him (since Paul Fournier is the legal owner of his factory and now the merger of his company will be passed onto him), he reveals the whole truth and it has to be seen...Hubert de Tartas: Man is going mad... Man is going mad... [grabs Paul and start shaking him violently] AND I'M THINK I'M GOING MAD! EDMÉE! EDMÉE! EDMÉE!