As far as I can tell GPUs can easily run at much higher temperatures than CPUs without problems. Aren't they both made out of the same materials? Why are GPUs capable of operating at temperatures that would kill CPUs?
GPUs will similarly suffer meltdowns running at high temperatures for prolonged periods of time. If you surf the hardware support sites, you will realize that the occurrence of GPU meltdown far exceeds CPU meltdowns.
One advantage GPU has over CPU is that they usually have a larger area to play with in terms of heat dissipation, at the same time the GPU chip is not constrained to a die as small as a CPU, thus enabling a GPU chip to have better tolerance.
At the same time, CPU thermal shutdown is usually set conservatively - most BIOSes by default shut down the CPU when it hits 70 degrees Celsius. Unless you manually override the BIOS settings, it is not often a CPU gets pushed beyonds its limits (thus having less reports, and perceived lower failure tolerance). However, GPU overclocking is extremely common, and many situations arises where people push GPUs to extreme temps - thus resulting in a perception that GPUs have higher temperature tolerances than CPUs. Not true - I have seen CPUs go up to 100 degrees Celsius and still remains stable.
Because they consume way more energy when displaying graphic heavy stuff. Consumed energy transforms into heat.
They may be made from the same materials, but the overall demand on the GPU is far greater than the one on the CPU depending on the applications and state (idle or workin 100%).
Oh, well, new answer then:
Because they aren't made of the "same" material. Sure, the core material is the same.
But like I previously said, since the energy demand on GPUs is far greater than on the CPUs (which translates into heat), the GPUs must be able to withstand high temperatures, thus the materials are changed and adapted accordingly and different cooling techniques are implemented.
Excatly HOW they are changed and adapted, I believe those are patented secrets of each GPU manufacturer.
Which is why they can run with temperatures upwards 80 °C and more without trouble. I've seen NVIDIA GPUs running at 95 °C without trouble for a long period of time.