Originally Posted by
alan s
My back was sweating at 32F this morning without a backpack. Why would anyone willingly strap a heat trap on an area that provides a great deal of cooling?
This post made me remember one other negative I have found with a backpack - most of my cycling wind vests or wind breakers have venting in the back. Unfortunately wearing a backpack blocks this venting so you don't get any benefit from it. This means often that wind shielding layer in front causes even more sweating in the back as you don't have a way to the heat to get out.