Well, what can I say. I've always been in love with wanting to live in the wilds. Always have, even when I was a young boy. I've done survival treks numerous amount of times. Some were good, some not so much, but I will tell you this. I found that a bad survival trek is much better day than a bad day back in society.
I guess I find bushcrafting or wilderness survival to be more honest that living in society. In the wilds, rules are quite simple and dare I say, common sense. If you're cold, find a way to get warm and out of the adverse conditions, make a shelter. Thirsty, find a way to get water and purify it if necessary. As to warmth and purifying water, know how to make a fire in a multitude of ways, don't be reliant on one way. Lastly, hungry? Come on! Anyone from Western Civilization, especially if you're American, you have at LEAST a weeks worth of emergency storage. We're just so used to eating 3+ meals a day. Dropping it down to 1-2 meals a day, and unless you have a medical issue, won't hurt you.
If you noticed I have a theme on survival priorities, though they can be flipped around at times. Of which the importance of survival for me goes as: Shelter, Water, Fire, and lastly, Food. Though I HAVE switched things around like Fire than water due to terrain and weather.
I also follow the priority of 3's.
You have three seconds of surviving without thinking. (Thought.) If you find yourself in a emergency/survival situation you need to get your thoughts in check otherwise you'll succumb to panic, as we all know that panic will kill.
You have three minutes without air/oxygen. If you have trouble breathing, find a way top fix that otherwise in approx three minutes you're done. I also like to include this with Thought version, as a way to calm down and control the out of control thoughts (Panic fuel) take deep breaths. If you combine the Thought and Breathing in a emergency/survival situation you're going to be ok.
You have three hours without adequate shelter. This can be varied, but at certain terrains, times of the year, even weather, you can have only three hours to live. Lot of people would liken this to hypothermia, and in a way they're right, but they also forget its polar opposite. Hyperthermia, sounds similar, but they not, but will affect you the same way, make you dead. HyPOthermia is where your body core temperature drops and you start shivering. HyPERthermia is the exact opposite. Its where your body core gets dangerously high, which occurs in the desert. Yes, you CAN die in a matter of hours in the desert. High heat, very dry air, and intense sun can bring you down fast before you know it.
Some definitions:
Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6 F (37 C). Hypothermia (hi-poe-THUR-me-uh) occurs as your body temperature falls below 95 F (35 C).
When your body temperature drops, your heart, nervous system and other organs can't work normally. Left untreated, hypothermia can eventually lead to complete failure of your heart and respiratory system and eventually to death.
Hypothermia is often caused by exposure to cold weather or immersion in cold water. Primary treatments for hypothermia are methods to warm the body back to a normal temperature.
Hyperthermia is a condition where an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. When extreme temperature elevation occurs, it becomes a medical emergency requiring immediate treatment to prevent disability or death.
You have three days without water. Again, this depends on a numerous of things, but this is a general average. In wetter climates, it can be a bit longer, where I live in the desert, it can be much, much faster. Dehydration is a horrid way to die.
You have three weeks without food. This can be of some debate. It depends on body mass, how survival muscle (Fat) you have on you, the environmental conditions, the amount of physical exertion, the over all physical condition of your body, and medical condition. I might also add in the training you have done with your body. IE: you fast at least a day or two or more every so often. This will train your body not to freak out when the food stops and start consuming itself. Over all, the general consensus is approx. three weeks without food before you start having issues.
Lastly, and this is of some debate, you have Three months with out Companionship or hope. Basically, this means three weeks without Love, Companionship, and especially Hope, you will just give up out of despair and give up the ghost or at the very least stop trying to live. If you're a very social person and like being sociable, this can be shorter, but if you have hope you can use that. For some, people who can be alone with themselves, they can last longer. But in the end, as human, we are social animals, we have to have some form of communication otherwise depression and despair starts to set in.
I'll use the show Alone. You have skilled experts being dropped off in the wilds to live out there as long as they can and can tap out at any time. Yes, accidents do happen and they have to tap out, but in the end, what most tapped out was due to the fact they missed their family, they got lonely.
People NEED some form of communication. Even the mountain men of old who liked being by themselves sought out communication from time to time. Those on Alone that lasted to the end, had a key ingredient on lasting to the end, and that was Hope. Hope to keep pushing to bring something back to the family, a ways to help them. That is what gets them though the lonely times is the hope of making it to the end and doing them proud.