I would try to take the unit outside the wall enclosure and test for a while. The 10G sfp+ RJ45 (10Gbase-T Copper) modules I occasionally use get really hot, no matter how much traffic. Maybe that adds a lot to ambient temperature in a very dense environment?For testing, you could also try a 1Gb/s sfp+ copper module, although you won’t reach the usual traffic. But they are much cooler.