The books enumerated below will provide crucial guidance and support for you in doing this. In other situations, you won't even be able to hope for professional help. Bones are broken. Babies are ready to be born. People get food poisoning.
Bare feet step on fish-hooks.
Kerosene and gasoline stoves and lanterns explode. In the face of these events, people may be slightly or gravely injured. Neither should you. And everything in between, plus an excellent listing of physical symptoms that, in the case of systemic illness, can help you tell the difference between fish poisoning, a colitis attack, and a diabetic siezure, for example. Some are cheaper.