I normally don't subscribe to the obligatory "get training" that everyone seems to apply to every shooting discipline, but first aid is an area where this absolutely applies. I would highly encourage those trekking into the field to consider a AHA BLS course or even more advanced trauma options if you are planning on carrying more critical emergency gear. Also advise assembling your own kit so you know exactly what is in it.
I see people mentioning tourniquets, but which one are you using, and can you access it and apply it to yourself fast enough before you lose consciousness from an arterial bleed?
People mention chest seals, but if you get them on, how are you going to treat/prevent tension pneumothroax if you are alone in the woods?
NPA/OPA's - if you are really going this far, do you know how to size them to the patient and how to/when to use them? Nobody wants to regain consciousness with an OPA in their mouth that no one knows needs to be taken out.
Infections and broken bones are bad, but hemorrhaging, airway problems, shock, and hypothermia are going to kill you before those are.
Chest seals? Do we need those? I carry them…..wish I understood them better.
Chest seals basically serve as a one way valve in the event you or someone else has a penetrating chest wound which punctures a lung. When you breath in, air enters the lungs and the chest seal suctions against the external wound, sealing the chest, and allowing you to create the negative pressure to inhale. When you breath out, positive pressure pushes the seal out, allowing air to vent so you can replace the air in your lungs. For a hunting situation, getting shot by a negligent hunter, getting impaled on a tree branch, or mauled (antler) are probably the most likely reasons you would want to carry one. The problem is after their application, air can fill the thoracic cavity surrounding your lung and cause it to collapse and even put pressure on your heart and intact lung. That is tension pneumothorax which will kill you as well if not treated with a catheter which involves sticking a thick needle between your ribs. If you have ever seen the movie
Three Kings, there is a fairly decent depiction of this with Mark Wahlberg's character using a bit of older treatment technology.