The gas chamber is often associated with the use of poison gas as a method of execution, and the dream may be expressing your own fear of being suffocated or overpowered by something or someone else.
If you dream of being in a gas chamber, it may symbolize a feeling of being trapped or confined. The dream may be expressing your own feelings of being stuck or unable to escape from a difficult situation or relationship in your waking life.
If you dream of someone else being in a gas chamber, it may symbolize a fear of losing someone or something important to you. The dream may be expressing your own anxiety about the well-being or safety of someone you care about, or a fear of losing something valuable to you.
If you are escaping from a gas chamber in a dream, it may symbolize a sense of triumph or victory. The dream may be expressing your own sense of accomplishment or success in overcoming a challenge or obstacle in life.