Au secours!
This is the French equivalent for “Help!” Use this phrase to quickly attract attention when you need immediate assistance.
Quelqu’un s’est blessé, au secours! (Someone is hurt, help!)

À l’aide!
Similar to “Au secours!”, “À l’aide!” also translates to “Help!” It is another urgent call for assistance.
Je suis coincé, à l’aide! (I’m stuck, help!)

Appelle une ambulance!
This means “Call an ambulance!” Use this instruction to ask someone to contact emergency medical services.
Il ne respire pas, appelle une ambulance! (He’s not breathing, call an ambulance!)

J’ai besoin d’un médecin.
It translates to “I need a doctor.” This sentence is crucial if you’re in need of medical attention.
Je me sens mal, j’ai besoin d’un médecin. (I feel sick, I need a doctor.)

Où est l’hôpital?
Asking “Where is the hospital?” could be vital to getting yourself or others the necessary medical care.
Nous avons un cas d’urgence, où est l’hôpital? (We have an emergency case, where is the hospital?)

Il y a eu un accident.
This means “There has been an accident.” It can alert others to an emergency situation you’ve witnessed or been involved in.
Restez calmes, il y a eu un accident. (Stay calm, there has been an accident.)

Appelez la police!
Meaning “Call the police!” It can be used when you require law enforcement.
Ma voiture a été volée, appelez la police! (My car has been stolen, call the police!)

C’est une urgence.
This phrase can be used to communicate the seriousness of a situation; it translates to “It’s an emergency.”
C’est une urgence, il faut agir vite! (It’s an emergency, we need to act fast!)

Je suis perdu(e).
To express that you’re lost, say “Je suis perdu(e).” The (e) is for female speakers.
Je ne reconnais pas cet endroit, je suis perdue. (I don’t recognize this place, I am lost.)

Je ne peux pas trouver mon enfant.
If you cannot find your child, say “Je ne peux pas trouver mon enfant,” which means “I can’t find my child.”
Je ne peux pas trouver mon enfant, pouvez-vous m’aider? (I can’t find my child, can you help me?)

Il y a le feu!
If there is a fire, yell out “Il y a le feu!” to alert those around you.
Sortez rapidement, il y a le feu! (Get out quickly, there is a fire!)

Arrêtez-le/la!
In the event that someone is committing a crime or you need to stop someone, “Arrêtez-le!” for males or “Arrêtez-la!” for females means “Stop him/her!”
Arrêtez-le, il a pris mon sac! (Stop him, he took my bag!)

Being prepared with these French expressions can make a significant difference in an emergency. Keep them in mind when traveling to Francophone regions, as they might just be what you need in a difficult situation. Remember that proper pronunciation and remaining calm are equally important in conveying your message effectively during emergencies.