WHERE THE WEIGHT SITS

Foam panel back systems (as seen on the Berghaus, left), hold the load close to your back, relying on channelling to vent heat. Suspended systems (like the Osprey, right) have a mesh panel that sits against your pack, while the load is pushed outwards, creating a space for air to circulate. The upside is usually better ventilation; the downside is, some walkers feel a suspended system affects their balance (and they’re usually pricier).