Support BladeForums! Paid memberships don't see ads! You need two plastic bottles for this one. This one I learned in my desert survival training in the army, It has worked for a lot of the guys, and it good for a self rescue or escape en evasion type scenario when you have to be on the move. First step is to urinate in one of the containers. Attach the other bottle to the one with the urine so that they lay almost flat, and wrap the mouths of the bottles together with some plastic (the wrapping some plastic bottles have works well, if you have a lighter you can heat seal the plastic) or duct tape (whatever you have with you) to for an air tight seal. Find a place with a lot of direct sun light and burry the empty bottle completely. The heat for the sun will disinfect and evaporate the water content in the urine bottle and it will condense in the empty bottle. Very carefully remove the urine bottle and enjoy the water. Even though urine is mostly water it is not that safe to drink directly, it has some waste products in it like sodium, potassium, and trace alcohol if you had a few beers the night before. Your natural kidneys filter does a big job in getting these waste products out. This method can also be used to purify any stagnant water you may come across. Stay safe out there.