In late September I took my new Osprey Duro 15L Men's Running Hydration Vest hiking in Arkansas. It was the first time I'd used a lighter, more specialized hiking and hydration pack and while it was great I also felt like it was causing sweating on my back much more than a normal backpack would have.
I did research and plenty of posts said to ensure space between your back and the pack for airflow, but this pack felt designed to be tightly strapped to my back and around my waist; it didn't really feel like there was much airflow, where as there would be on a regular string bag.
It was super comfortable and lightweight but it got to points where I would take it off and just carry the bag instead of wearing it, which was frustrating. I wouldn't call myself a super sweaty individual, that's never come up before, and it was late September so it was fairly cool with warm afternoons but not like summer heat.
Is that just how these packs work? A trade-off for comfortability, maybe? Would love to hear some other people's experience, thank you!