There isn't a lot you can do for a head injury like the one we saw in this video. Either the wound is bad enough the casualty dies, or it's not and they're able to make to the hospital.
Never apply direct pressure to a head wound if you suspect fractures because you could push sharp bone fragments into the brain, causing further damage.
The only other things you can do for the casualty is try to stabilize the spine to prevent additional injury, and call 911.
Get medical gear at Mountain Man Medical
Get a good Sling, and USE it!
North American Rescue Combat Application Tourniquet (CAT)