Today on The First 40 Kilometers, we discuss the metric lifestyle and how it applies to backpackers and bushwhackers. Then, as promised in episode 68, you’ll learn the top 5 reasons to carry a hydration bladder.  Next, on the SUMMIT Gear Review, a pair of shoes that provide the perfect climate for your feet.  On the Backpack Hack of the Week, learn how to remove sap with things from your pack.