Hi!
The requirements for Crash Dive on PC are actually really low; it should run fine even on systems with integrated graphics (no discrete GPU).
If you're limiting your FPS to 30, it sounds like frame rate is not an issue. Why are you concerned about the temperature of the GPU? Most discrete GPUs have active temperature control; if the temp gets too high, the fan should spin faster to cool it down.
If your GPU is getting hot enough to cause issues (lock-ups, blue-screens, screen garbage), then you have a hardware problem. If you aren't seeing any of those issues, then you have no problem.
-Scott