A few simple actions can save a life while you get to a hospital.
Heavy bleeding: press hard on the wound with a clean cloth and keep pressing. Raise the part if you can.
Burns: cool with clean running water for many minutes. Do not put oil, toothpaste, or ice.
Choking: bend the person forward and give firm blows between the shoulder blades.
Fits: move hard objects away, do not hold them down, and do not put anything in the mouth. Turn them on their side after.