Level of difficulty (1 being easiest, 10 being hardest): 3

Bandanas are not just for looking bad ass on a hike. They're a useful survival tool in both cold and hot conditions. They can protect you from both the sun and a cold breeze. If you are lucky enough to find some fresh water, a bandana can act as a filter, purifying the water to some extent. If you are unlucky enough to find yourself with an open wound and need to stop the bleeding, and bandana can act as a great makeshift tourniquet.

[via adventure.howstuffworks.com]