A gas mask in a dream can often be a symbol of fear or the need for protection. It can suggest that the dreamer is feeling overwhelmed by some situation or emotion and is looking for a way to block it out or protect themselves from it.
If the dreamer is struggling with a sense of inadequacy or vulnerability in their waking life and they turn to put on the gas mask represents their desire to protect themselves from these feelings. It may suggest that the dreamer is trying to hide their insecurities or shield themselves from criticism or rejection.
Also, it may suggest that the dreamer is feeling trapped or oppressed and is seeking a way to escape. When the dreamer is feeling suffocated or controlled in their waking life and they are wearing a gas mask represents their desire to break free from these feelings.