Cooler than the old Asicminers .333 in my hubs, U1 and U2 temps about the same.
5v at 5a PowerAdapter on each hub - 5 Ux per hub  35 to 42C with large destop USB fan resting on the cluster of devices.
110 is nothin. Temps taken with a laser gun on wide scan.

Without a fan of some sort they get hotter, 50 to 60c or so. Not hot enuf to melt hub or anything, it just cuts down their lifetime runnin hot.

ALL U1 and U2 set at .0981 volts for 2ghz average on bitminter. I like to allow 1amp per stick, ( I like the margin ) everything overbuilt, not stressed.