Hypothetical situation, thoughts?

Hi, so I am going through a lecture about trauma and I began wondering what nurses are allowed to do in emergency situations in “the field” or life outside the hospital? If your assessments of a person says they have a tension pneumothorax, their trachea is already shifted and etc, and you can tell time is running out, do you have the ability to create a hole into the person’s lungs to save them? What if they are aware and nod in acceptance of receiving that care knowing it is outside the “usual” scope of a nurse but may possibly be their only chance of survival? What would you do? What is allowed? How far would you go to help someone live if you know that immediate action is required? What is the legal course of action?