Hey buddy.
The primary objective is to
keep them breathing and
stop them bleeding while you can
get them to help, or help to them. A big bleed or blocked airway will kill first. The next biggest threat is shock. Keep a cellphone in a zipped inner pocket to increase the chance of being able to communicate - if there's signal where you come to earth. Be prepared to triage casualties. Do a HEST/HEFAT trauma first aid course, with a strong Remote Areas component.
My kit contains:
- CAT Tourniquet (mil type for 'single handed' operation)
- Pressure bandage with lever (generally known as 'Israeli' bandages - remove the 'Made in Israel' sticker if you're travelling in some areas)
- Celox or Kwikclot or similar haemostatic agent.
- SamSplint
- The most powerful painkillers that won't get you arrested (so no morphine unless you have a friendly doc who can get it for you, then make sure you carry the prescription)
- Gaffer tape (I've seen gaffer tape and superglue used to hold together traumatic injuries in the short term)
- Leatherman (which you'll lose if you try to check in on a flight from any commercial airport, of course!)
- Cling-film is good for covering burns
- Aluminium survival blanket
Add
- a compass
- all-weather matches
- 5mt loop of paracord
- water purification tabs,
- emergency cell phone with good battery life and strong signal - I use a Nokia 3310 with a TravelSim SIM card
- signalling mirror
and you have a decent emergency travel kit that should weigh in under a kilo. Put it in a 'grab bag' that is never out of reach.