My Jacket's Not Working!

Who is a fan of Man vs Wild? If you are then you’ve seen the extreme weather conditions that star host Bear Grylls, the youngest man to ever summit Mount Everest, is subjected to on a weekly basis. The modern day MacGyver must keep his body at a survivable temperature even in sub zero environments. Being that he’s a former member of the British Special Forces I’m sure he is familiar with what materials to wear in order to keep himself alive. But think about the common man…or woman…that goes out for that weekend of fun to a local state park for a little camping, hiking…a little R&R if you will. And let’s say that the temperature suddenly drops to freezing temperatures. Will he or she know how to properly bundle up?

The reason I pose this question is due to a topic that was recently introduced in my Heat Transfer class. Heat Transfer is an extension of my Thermodynamics classes in that it explains the behavior of heat on a smaller, more detailed scale. By this I mean, in Thermo we just learn how to quantify a certain amount of heat, Q that goes into or out of a system. In Heat Transfer we learn the definition of Q, for example Q = -kA dT/dx…so basically we now know all of the little parts that make up the entire Q value.

What really got my attention the other day in class was a thing called the Critical Radius. The Critical Radius is a distance from a heat source at which if you were to stop your insulation barrier, you would lose the largest amount of heat; Which means that if the critical radius of a certain material is 2 cm, you would lose more heat from applying 2cm of insulation than if you were to supply 1.5 cm of insulation. Counter-intuitive yes I know. Some of the things I learn in this major never cease to make me think.

Which leads to the tangent I’m perusing right now. Is it possible that you could be lost in a cold climate, a camping trip gone bad if you will, and actually put on too many clothes? While you think you are doing what we call “bundling up,” you’re actually putting on the clothes that will make up your soon to be deathbed! It doesn’t get much more ironic than that, don’t you think?