The essence of first aid is the blood / circulation.

Its kinda like plumbing

• Where do you want it to go?
• Where do want to keep it away from? (Swelling, cuts).Consider Ice, Firm Bandages, Elevation?
• Can you make sure it has oxygen in it? (breathing).Consider Rescue Breaths, CPR?
• Is the pump (heart) going too fast?  Consider Calm, Reassurance, Raise legs?
• Does it have sugar? (diabetes, hypothermia) Consider Sweet drinks, jellybeans?
• Do you want to slow it down?(Poisonous bites & stings)Consider Bandages, Reassurance?