Backpack for August?

[Weddingnyc]

We also have the quecha backpacks (in fact, we have 5, one each) they are fab for each of us on the plane, picnics, school trips. However, we felt that they made our backs sweaty so we opted for bumbags. The kids have one each for their sunglasses and bits and bobs, I have a Kiplin Multiple (phone, glasses, keys, suncream, power bank) and DH has a man's bumbag for similar stuff. It also meant I wasn't rummaging looking for everyone's items every 2 minutes

[vanderbar]

We got insulated back packs - in an attempt to keep the cool in. So an bottle of frozen water (or two) in each day to help keep everything (a little) cool.

[Fraser789]

I've got a Tresspass backpack it's water proof and has 2 drink holders on the side. It's quite big though does anyone have any backpacks that will easily fit in the free lockers at Universal?