Is There a Backpack that Doesn't Make Your Back Sweat?
Air cooling, the well ventilated backpack
Tatonka Storm 30 Hiking Rucksack with Back Ventilation and Rain Cover for Men and Women 30 Litres, Unisex - Adults, Hiking Backpack, 1533.021, Titanium grey, 30 liters : Amazon.co.uk: Sports & Outdoors
How Well do Ventilated Mesh Backpacks Work? - SectionHiker.com