Their is something different between the model 2200's and the older model 200's. I have ten model 200's and three of the model 2200's. I have them stacked in three stacks of three and one stack of four, and all stay in standby mode until I trigger them with a 12v signal. In standby mode the 2200's stay at about 108F-118F while the 200's stay at about 90-100F. They are located in a room kept at 75F and of course the highest temp reading for all amps were in the transformer region. I take the readings first thing in the morning after the amps have been off for 7-8 hours and I used a Fluke IR temp reader which is pretty accurate. I thought that the higher temp for the 2200's were due to their being new and not broken in but I have had them for several months now and nothing has changed.
As far as heating up during use, I have had no problems with the 200's getting anything other than very warm when pushed hard in a four ohm load. Unfortunately I am not sure how hot the 2200's get since they have fans on them during use (When the TV is on they are blocked by the cabinet door and therefore do not get any airflow so I have fans cut on whenever they are in use).
Also someone had mentioned using fans to cool the amps but the fans made too much noise. Their are several ways around that. First us only DC fans, AC fans can generate noise in the amplifiers and heard through the speakers. Once you have picked out a DC fan(s) you can control the speed in three ways (probably more but these are the ones that I know). If you understand ohm's law than you can place a resistor inline with the fan and reduce the speed that way (easiest to find and cheapest), or you can buy an adjustable wall wart (AC-DC transformer) that has an adjustable voltage switch (radio shack carries these, fairly easy to find and somewhat cheap), or last you can buy a DC fan speed control that will control the speed with a dial (hardest to find and most expensive).

Hopefully this will help some.