In a survival situation it’s important to remember the Rules of Three.
Rule of Three minutes
If someone is not breathing then CPR needs to be carried out. One cannot survive without oxygen for as short a time as three minutes. Get training to learn the proper technique for CPR. Contacting the Red Cross is a good place to start. The only thing that could possibly have a higher priority than CPR would be arterial bleeding. The bleeding needs to be controlled and then CPR started as soon as possible.
Rule of three hours:
In extreme temperatures hot or cold, without proper shelter, after three hours in extreme heat one can suffer heat stroke or exhaustion. In extreme cold frostbite and/or hypothermia would be a great concern. When out on the trail, being prepare is not just a saying for the boy scouts, but could be a matter of life and death. A simple space blanked carried with your first aid kit can reflect your body heat back to you in subfreezing climates as well as reflect the heat from a baking sun.
Rules of three days
In a survival situation, once everyone is breathing, not bleeding, and shelter is found, the next priority is water. The body will become dehydrated in three days without water. We lose water in many ways. He hot climes we lose water through perspiration, but even is frigid climates one can lose moisture from ordinary respiration.
Rules of three weeks
After three weeks the body will need nourishment.
Being prepared is no accident. A good place to start, when you venture out into the wilderness, whether it’s a day hike or week long backpacking trip is the Ten Essentials. The Ten Essentials is more than just 10 items. Look at The Ten Essentials as 10 essential categories that should be carried
The Ten Essentials need to be carried on every trip, but most importantly it is essential to know how to use what you carry. Practice with your ten essentials ahead of time not when you need them to survive.