What's your HD temperature in comparison to the CPU and GPU temps? Are you using and fan control software to "boost" the fans for more efficient cooling under load? It's not running hot when at idle, is it?
SSD are cooler than HDD but I doubt the heat you are feeling is coming from your HDD. Its coming from your GPU/CPU most likely, unless you're doing a LOT of reading/writing then where your HDD is might SLIGHTLY heat up.