Recently went to a vet for an exam and they mentioned to have a "humid box" like an enclosed space/hide and put damp paper towels in for beardies to "cool down" in, similar to humid hide for geckos. Has anyone else ever heard of this?
Reason is because beardies would "dig to find moist dirt or soil beneath the surface to cool off in the wild"
I asked about contracting URI and was told that would be a risk only if the entire tank is humid or exposed to high humidity 70~ constantly, but a focused area is fine.
They do burrow in the wild both to cool down during day/warm up at night or in winter and for security. I go about simulating this in a different way. Having a gradient across the tank allows them to move over to a cooler side to cool off if they want to. Building levels lets them climb or hide. I have fleece blankets on the ground to allow them to burrow. Damp towels may allow for evaporative cooling but I haven't found this necessary at all if there is a proper temperature gradient across the tank.
Lots of reptiles benefit from humid hides, they just aren’t popular with beardies for whatever reason. The only reason for concern would be if your dragon spends a lot of time in it all year round. Keep the substrate clean and fresh, and check for mold etc regularly.