Try downloading and installing MSI Afterburner. It comes with Riva Statistics Server (RTSS). Once installed, set up the On Screen Display to show GPU temp, CPU Temp, and GPU Fan Speed. It can display a lot more information, but for troubleshooting temperature issues, this will be enough. Once installed start COD and start playing. Keep an eye on the OSD and note how hot the CPU and GPU is getting. If the GPU is getting hot, note the GPU Fan Speed.
Let us know the results.
If you need a hand configuring Afterburner let us know.