I cant vouch for 48 devices, but I went from a 3Com Hub to a Linksys workgroup 5 port Switch and I noticed that the Hub always seemed to be pretty warm, while the switch always seems to run cooler. With a switch, all of the devices are partitioned off in their own area and only the selected parties are sent messages or packets from one sender to the other. However, a Hub sends all messages to everyone which causes many collissions and then data has to be resent.
Before you switch ask yourself if what you are using is doing the job and if you are happy with it?
I know Cisco developed some technology for doing Virtual LANs that allows switches to create subnets. This is one thing certain switches may be capable of doing and it is something to look into. I think this is because a switch costs a little less than multiple routers. If you do not like my post feel free to point out your opinion or my errors.