Great information! As a trained Occupational Safety Professional with over 35 years of experience, I would add; to remain calm, most struggle to remain calm during an incident; Stay focused on the individual and treating the injury and providing aid until help arrives if needed. one of the main goals is to put the injured individual at ease while they are being treated.
In my career, I have dealt with fatalities, serious injuries, and minor injuries. you do the best you can and end the end you know you were there for the injured and did what you could to help.