Keep in mind that computer temps are almost universally measured in Celsius. So, your CPU is 49C and GPU is 100C. Your CPU temp is fine, really good even, but your GPU is running too hot. You can keep it cooler by adjusting the GPU fan speed or adding more fans to your case. Alternatively you could replace the thermal compound on the GPU, or if you have it overclocked, dial back the overclock so it doesn't run so hot.