It's been known for some time that most datacentres are running too cold. It still seems to be common recommendation to aim for 20-22 C, but this is an outdated idea and a waste of cooling energy. Rackmount systems in a datacentre should be aiming for more like 27-29 C (80-85 F) intake temperature, and tower servers might be able to get away with quite a bit more, depending on the case and airflow.
You may wish to check your CPU temperature for reassurance - but check against the specs for the model, as different CPUs have very different normal temperatures. For example, Nehalem Xeons can run up to 76 C according to the spec sheet, so I wouldn't start worrying if you found they were running at 60 C.
Servers in the corner of an office are more likely to experiance thermal problems due to build up of dust than high room temperature. Take the side off once a year and check for build up of dust in the fans.
If you're not happy with the CPU temperature, you could open the cabinet door or move the servers out. Your average office temperature of 21 C is plenty cold enough to run servers in. Your office would have to be much too hot for you to comforatably work in before you need to worry about the servers.