Actually as I have thought more about having the mesh in back probably isn't all that bad of thing to say the least. The shoulder blades sit right behind the heart, where all the heat is being produced. The one thing I do like about what I'm wearing right now is I don't have a problem with it until it gets up near the freezing mark than I start to sweat in between the shoulder blades. Colder temps don't present any kind of problem until it gets so cold that I add the fleece pullover. I need to remake the top layer so it only puts the insulation on the front side and nothing on the backside. Protect from the cold wind but let the back act as the 'reflector' to get rid of the excess heat.