I have a Camelbak M.U.L.E. The padding that rests on your back when you're wearing it is quite comfortable. As long as I'm moving, and the air is hitting me good, I have no problem with uncomfortable back sweat. I usually carry 2-3L of water along with a towel, energy bar, and a multitool. I also wear breatheable athletic shirts and cycling jerseys. If its especially hot, my back does get a little wet regardless. Still, its the most comfortable backpack I've every worn while doing anything physical in the heat. I do think the special padding only works right if you're wearing a breatheable shirt, though.


-Matt C.-