Don't panic - it's OK, just like your epidermis, your boundary layer has been showing for quite a while.
So what exactly is a boundary layer? In a sense, your boundary layer is where you interact with the air (or water) that surrounds you. It isn't there to help or hurt you, but rather, it is a consequence of the characteristics of your body (such as body temperature and the amount of moisture on your skin) as well as the characteristics of the air that surrounds you.
In fact, on a warm summer day, you can see the boundary layer between the hood of car and the air that surrounds it. The air surrounding your car is warmed by the hot hood, and being warmer than ambient air, the air rises and mixes the cooler ambient. This area - where the air mixes - is a boundary layer.
For amphibians, the boundary layer is an important barrier between their skin and the environment. This is especially important for lungless salamanders because they maintain moist skin in order to breath. However, by being leaky, salamanders risk drying out. Under certain conditions, the boundary layer can be (relatively) thick and play an important role in determining how quickly they dry out. The longer it takes the dry out, the longer a salamander can walk the forest floor in search of bugs to eat and a mate.
But how do you measure a boundary layer? As you can see below in the figure, it becomes ugly quickly. For most people, delving into dimensionless analysis is not necessary. But understanding boundary layers can help you make sense of the world around you.
Now go bundle up for the cold weather - and keep your boundary layer close.