What could cause the engine temperature to suddenly rise while in AC mode during a traffic jam in summer?

If the fan is broken, the temperature might rise after parking for a while, showing that it's too high. Replacing the fan should fix the issue.

Park the car and turn on the air conditioner to check if the fan is spinning. If it's not, the fan controller might be faulty.

I recently had the same issue. Have you solved it? I'm afraid to turn on the air conditioning.