running hot

Hello,

I am running a 21.5 in. iMac from late 2009 that has 4gb of ram, a 3.33 GHz Intel Core 2 Duo Processor and ATI Radeon HD 4670 256 MB graphics, and I am worried that it is running too hot. First of all, when I am completely at idle, my CPU is running at 46º C, but the part that I am worried about is that my Power Supply Heatsink is at 80º C. Then, when I am starting to get into my usual stuff (such as research that requires multiple tabs open, and word documents, and sometimes one or two other programs, the CPU runs at roughly 60º C, and the power supply heatsink hits 91º C! In addition, I play games, but I have not run the program that tests the temperature because I just got the app, and I am behind on work (so I don't have time for games).

Well, it is time for the question, is this too hot? 196º F seems to be too hot for it to be running, but I may be wrong. (Also, is it normal for me to be getting crazy amounts of lag when doing research?)