Splint the broken bone. With duct tape, string, or an Ace bandage, fasten the branch along the bone, making sure to secure the splint below and above the break. A splint should maintain the bone or joint in its proper position, prevent further injury, and alleviate pain. For an arm or wrist break, consider using a T-shirt as a sling after splinting the broken bone. Ask yourself if the situation is an emergency.
Broken bones are emergencies if a femur, rib, pelvis, cranium or vertebrae breaks.
It is also an emergency if the break is cutting off circulation to any part of the body. In these cases, go for help as soon as possible. In all other cases, ask if the person can walk out or whether you need to get help to carry the person out. Try to determine how seriously the person is injured and go for help. The best way to combat altitude sickness is to take it easy for a few days and drink more water than you've ever drunk in your life.