Fire
Knowing how to build a fire can save your life on a cold surprise night in the wilderness. Always have matches with you, even on a day hike, and gather dry pine needles and dead leaves to light first. Continue to add larger dry items slowly as each layer catches fire.
Bathroom
Girls must urinate differently than boys without the luxury of a toilet. If you have to go, find a good tree to hide behind far from any water source. You can hold onto the tree or sit on a log to help you balance. If you have toilet paper, do not leave it in the woods. If not, you can use a smooth stone, soft leaves, or just air dry.
Animals
The wilderness is where wild animals live, from a swarm of bees to mountain lions and bears. If you come in contact with one of these animals, it is imperative that you stay calm and do not run or scream. These actions will most likely provoke the animal rather than scare it off.
Shelter
There is no need to be very strong or to create a huge fortress for you and all your friends for a night. Take a few logs or planks of bark and lean them against a large fallen tree or boulder, leaving just enough room inside for you. This will keep you warm and protected from the elements.
Layers
Never leave for a trip to the wilderness without bringing at least three layers of clothes to put on in an emergency. Girls often get cold faster than men, and the extra warmth will be appreciated if you get caught in a storm or at night.