Regardless of the situation, the best tool to survivability is a positive outlook.
Once a person realizes they are alone Fear sets in. Fear is a natural reaction. Once you become afraid you need to stop and access your situation. If fear is allowed to take hold, it will lead to more trouble. Some studies have shown that lost people tend to veer right in their wanderings. However, frightened people veer left. The best reaction is to STOP and make the best of your situation where you are.
Trail of fear: The following issues will compound the misery of your situation. If you want to be rescued, you must conquer these.
Panic is the fight or flight reflex. It is a good indicator that you are in trouble. However, you need to conquer this feeling and set about getting yourself found. Do not try to save yourself unless you are absolutely sure of where safety is. If you wait, people will miss you and search teams (friends, family, police, and/or civilians) will be sent to find you. If you don't move, your chance of being found increases.
If you are in a clear area where you can set an SOS, then set the SOS, but do not leave the SOS unless you are in danger. In that case make an arrow showing your direction of travel. Leave sign of your passage by breaking branches and deliberately pointing them towards the way you are traveling. You can also bend tall grass, or leave rocks or sticks on flat grass pointing your passage. Stop once you are beyond the danger.
If you have become injured, it may not be noticed until the adrenaline from fear has subsided. Once you feel pain. Stop. Access your injuries and begin to treat them. Do not ignore your injuries or they will become worse and may incapacitate you. Rest is essential to remaining strong and in control of your situation. Do not use rest to despair.
Cold can set in at any climate zone. You must protect yourself from cold using leaves or grass as insulators. Build a fire. Any size of fire is a comfort. If you are able to build SOS fires, you need to have three fires far enough apart to be recognized as 3 fires. Aircraft flying overhead will recognize this as a distress call. Be extra careful if you are in the woods, don't cause a forest fire. Pile timber or use a large boulder to create a fire block on one side of the fire so the heat will be radiated in one direction.
Do not allow yourself to fall asleep or stop moving if you are not adequately sheltered from the cold. A symptom of hypothermia is fatigue. Your body starts to shut down in order to protect the vital organs from cold. The best way to do this is to make you tired. So you will stop using other organs. Sleep can be fatal. Make sure you are warm and not shivering. Shivering is the first clue that hypothermia is setting in.
Dehydration is a serious threat to your safety. It can dull your mind and affect your effectiveness. If you are thirsty, you must seek water. Water can be captured by digging a small hole and laying a large leaf in the bottom, or a jacket or something that can be cupped. Lay a piece of plastic, tarp, polyester clothing across the hole. Overnight dew will slide off the top piece into the "cup" below. Dew can also be collected from wet grass and leaves. A stream or lake is extremely helpful, though one must be cautious of contracting Giardia also known as "beaver fever". [Giardia is a parasite that infects the intestines of humans and animals. Giardiasis is usually a water-borne disease. Giardiasis may cause diarrhea, stomach cramps, gas, bloating, frequent loose and pale greasy stools, nausea, weight loss, and fatigue. Symptoms start about seven to 10 days after exposure to the parasite. Symptoms can last from three to 25 days or longer, and may last for months. Often a person can be infected and have no symptoms. In some cases, symptoms can return after you have started to get better. Rarely, arthritis and poor absorption of fats and vitamins can occur after a Giardia infection.]
As noted in a previous post, you can last longer without food than water or air. So it is not as serious as those two. However, it can impair your thinking if you are constantly fighting hunger pangs. It also makes you more susceptible to fear, cold and pain.
When you travel you should always keep energy bars (not protein) or some small food source on you. If you are hiking or camping, you should have a small survival kit with you that can help you out in times like these. However, there are many ways to obtain food from around you.
Fatigue is inevitable, especially in an emergency situation. You have to fight to keep your mind in a positive state so that you don't despair your situation. Help will come. It may take a few days, but as long as you stay put it will increase your chances of discovery.
When you have stopped, you should work to establish a camp. Continually looking for firewood or food around the area will keep you active and combat fatigue. Maintaining your fire will help keep you busy too. Build a shelter from what is around you. Use fallen branches, leaves, long grass to build your shelter.
It will come. Especially once all your immediate tasks are completed. So make tasks for yourself that can be completed at different times. Use night to sleep and make day time to work.
Tell yourself stories. Talk to yourself. These practices will create a more social feeling and help ward off feelings of despair.
You will feel alone, because you are alone. If you keep yourself busy and talk out loud, you will help to fight this feeling. It's okay to feel lonely, but don't give into it. You will be found and surrounded by people soon enough.